Multiple vaginal orgasms during sex, intense pleasure, too drain afterwards, a Ques.

Hi, I'm posting here in the Women-Focused Support group, because this is a TMI and sex question, I prefer to post it here. Thank you.

I'm sorry for the TMI post below, please feel more than free to skip right through it and not read it if you don't like to read TMI stuff.
And I'm sorry for my very basic English, and not so good English grammars. I'm Chinese/Vietnamese and English is my third language.

I lost my virginity late in life, to the man that is my husband. It been about 3 years that I'm sexually active with him--since Fall 2014 when I lost my virginity to him.. My husband is the only guy I have ever been with, he is my first everything, and my only sexual partner.
I have zero sexual experience prior to him, and I'm very prude.
No, I never use tampons a day in my life (I always use pads). No, I never stick my finger in my vagina. No, I Never use toys. No, I don't touch myself down there.. Yes, I'm that prude. Beside my husband penis, I never anything inside my vagina.
I know this sound strange considering how prude I am, but it not strange in China and Vietnam culture.

My husband he fully know how prude and inexperience I am.. He Not a kinky guy at.all., he very Vanilla, and loving and caring in bed; just like how he treats me outside of bed.
We are a vanilla couple, it just the traditional PinV sex between a man and a woman. No vibrator, No toys of any kind (it just his penis and my vagina). No a-n-a-l, No anything kinky.
We sexually compatible, we both wants the same things in bed. We both very vanilla.

As you know the above, I was a virgin when I sleep with my husband and I'm very prude. There is one question that is on my mind I always wanted to ask, I wonder if I'm normal or not. I ask it below:
Sex feels damn good. He kiss alot during sex, he also very caring and attentive. I do get vaginal orgasms (multiple vaginal orgasms) during sex. I love and enjoy sex with my husband.

In all fairness. My husband he 6'1" he tall and slim, he very lean. He does have muscles, but there zero fat anywhere on his body, it just lean meat.. And his stomach always totally flat, his stomach is just his lean meat and his skin. It genetics for him, he been this skinny/slim body type all his life.
He is the very lean and very slim man. And I'm the 4'11" petite and chubby girl here (so I know it not his weight that drain me, due to he very very Slimmm. Like I say, his stomach is totally flat--just lean meat and skin. I think it his penis that drain me).
No, he never hurt me, he very caring and attentive in bed. He always stare at me straight in the eyes, like stare deep in my eyes during sex, touch my face and look at my face expressions, and he kiss the whole time during sex (you know like down there he thrust, but up there he sucks/kiss my face, lips, neck, shoulder, breast, at the same time as he thrust). He even whispered asked "Does it hurts?". I know he cares for me.

Problem is, let me explain. Not just only he well-endowed but he beyond well-hung (I think in English language, you said he hung like a horse).
Him being very well-endowed it not a problem because as you already know there no man penis girth that can be bigger than baby head, so the thickness of his penis is Not the problem.. The problem here is not the girth, but it the "Length" of his penis--it him being beyond well-hung, you know it just sooo Longgggggggg (the length, in inches). And you know the woman vagina dept can only be so long.
At first began have sex with him, it hurts somewhat, but the pain was like 1x but the pleasure is like 100x. A short time goes by, I guess because I keep having sex with him so I adapt to his penis size, it no longer hurt anymore. It doesn't hurt anymore, now it been just pleasure and pleasure, the pleasure it intense, extreme pleasure.

I get Both clitoral orgasms and vaginal orgasms. The clitoral orgasms doesn't bother me, but it the vaginal orgasms that I wonder if I'm normal or not. Which I personally love love vaginal orgasms, the pleasure of vaginal orgasms it just too much, a million times better than clitoral orgasms and it last alot longer too.
Question below:
Have intercourse with him, I get vaginal orgasms, and I just completely lost in it, it like I don't even know where I'm at anymore. I mean I know that I'm in bed having sex with my husband, but I lost it, I don't even know I'm in bed anymore. Like ALL I know and ALL I can concentate on is how good his penis feels.
I can't even concentrate my eyes, I can't even control the movements of my eyes, let alone my mind concentrate elsewhere. All I can concentrate on his how good it feels inside my vagina.
It funny to say this, but even if the ceiling fall down, I probably wouldn't even know it, because the pleasure "down there" is just intense,--and that is ALL I can concentrate on.
......
You know vaginal orgasms is not a short duration and on the surface like clitoral orgasms.
Vaginal orgasms it alot longer duration and it way deep inside your vagina, the whole vagina, and the intense pleasure it comes and comes and it LINGER. It comes and linger and then another one comes.. The pleasure it just too much, it feels so good down there that you completely lost in it. I can't even control the movements of my eyes (my eyeballs roll back?), or my breathing, I pretty much was with my mouth open trying to gasp my breath.
I don't even know where I'm at anymore, unless he stop thrust me. Is that above NORMAL?

My husband can feel my orgasms, every single time. He can feels it and he can tell the exact number of how many vaginal orgasms I have. There times when he whispered and said I came. Well, yeah, I did orgasm vaginally, and he noticed. And then another orgasm came and I orgasm again.--It like mutiple vaginal orgasms. And he can feel it every time and know exactly how many times I came.

Here is the thing, we very vanilla. It just the traditional sex PinV (penis in vagina) sex between a man and a woman, there nothing kinky. So sex shouldn't drain me this much.
AND my husband is the one that do all the work, as he is a dominant man, and he wants to and loves to do all the work. I just lay there and enjoy it.. BUT then afterwards when he done/finished, "I'm" the one that drain (I guess it due to multiple vaginal orgasms so it drain me?). After he cums inside me and he removed his penis/he done. I lay there and like 2 minutes later I drift into a deep sleep, I'm like totally out. I just can't, just can't find myeself to stay awake after intercourse with him.
This happens everytime I have sex with him. I don't know if this is normal or not. I mean is this NORMAL?
Is this normal? Am I normal?
I always told myself to stay awake after the deed is done, but it never work. I'm just so drain, I have no energy. Like he cums/he finished, I lay there and 2-3 minutes later I'm just out. I drift into a deep sleep, I just can't find myself awake, at.all. There many times when I drift into sleep completely naked.
And this is regardless of sex in nighttime or daytime. When he work nights, we have sex in the daytime, and it the same exact result above.

My husband said it normal for me to be like this afterwards, but how can it be normal when he the one that do ALL the work, but then I'm the one that drain afterwards? Beside multiple vaginal orgasms that cause me to drain, I don't know what else can it be.
I'm just drain afterwards, it not just the linger from the vaginal orgasms, but it my whole vagina area/pelvic that like it drain. The pleasure it just too much.. I have no energy, I don't even have the enery for my legs to make it out of bed, let alone make it to the bedroom door, out to the bathroom.

I did ask my Vietnamese OB/GYN. Try to get an asnwer to why my vaginal orgasms it just extreme pleasure and intense, and why I'm drain after sex when he the one that do all the work. I did tell my OB/GYN that his penis "length" it very Longggggggggg.
She said a man with a longer penis, the longer length gives the ability to reach my cervix and beyond my cervix, to something call the "fornix", and that is what give me the intense orgasms.
She said something called the fornix, (sorry my English is very basic, I don't remember the exact English word, but it something fornix).--It the spot that way way pass the entire length of your whole vagina, even pass your cervix, further up your cervix. And when the longer penis reach that far, it stimulate that spot that give the extreme pleasure, intense orgasms.
I dunno, but that was what my OB/GYN said, and she said it normal that I get intense orgasms due to him hit that spot, the "fornix".
I look up the anatomy image of what the fonix is, and I found this pic, pic below:
I square where the fornix is in red, this is the spot my OB/GYN talking about.



She said because a longer penis, it can reach that far and stimulate that spot, that is where the intense pleasure come from. Because as he thrust he keeps stimulate that spot, so I get multiple vaginal orgasms. And from multiple vaginal orgasms, it drain me afterwards.
As you can see from the anatomy, the fornix it even pass the cervix, it further up the cervix. I don't know, but she said it his penis (a longer penis) it can reach that far and stimulate that spot give me intense vagnal orgasms, and extreme pleasure. I guess my OB/GYN was just trying to answer my question.
I'm sorry, I'm just rambling. I write straight out as the thoughts in my brain out come as it is, my thoughts it scatter all over the place. I don't think before I talk. Sorry.
I'm just trying to pinpoint down to the source of why I get multiple vaginal orgasms, why the pleasure it just too intense, to the point I'm completely lost in it, because ALL I know at that time is how pleasure it feels "down there". And I don't know why I have no energy afterwards, I fall into a deep sleep after intercourse with him is done (as I explain it above my questions in the underline, I asked if it normal or not, or if I'm normal or not?).

Hi jasmine, Actually your English is very good and clear.

I think everything you have described is totally normal, even being very sleepy after intense sex. It sounds like you and your husband love and care for each other very much. The two of you are lucky and I wish both of you well.

You and your husband are lucky people to have this together. Maybe in a little while you can ask him if you two can try some other stuff that isn't all "vanilla". It sounds like you are a great couple. He's good to you, and you are obviously in love with him and satisfied by him.

As for "is this normal", I think what you have is way better than normal.