I can't get her out of my head

I recently met this girl she is 3 years younger than me. (I'm 21.) We met off a dating app she said I was the first one she liked on there. The next night we hung out and she said she said she never had these feelings for someone so fast. I knew I liked her but I didn't get butterflies the way she said she did. We were together for the most part the next day. It's been several days since I saw her. I feel like I can't stop thinking about her and it's starting to get to the point where I'm obsessing over it and the fact she takes awhile to respond to me. Like for instance we had planned to hang out today but her friend came over last minute and she is taking awhile to respond on her phone and I can't stop thinking and feeling upset by it. I feel upset because I don't know if we are going to be together and I was really looking forward to it. I also felt insecure when she took awhile to respond a couple days back when her phone died thinking I'm not good enough or maybe she changed her feelings about me.
And that's the main reason I'm posting this how do I stop letting this take so much effect on me? I want to feel okay if possibly things weren't going to work out and to be happy with being alone with myself. This would be the first real relationship I'd be in. I feel not that it was rushed but that it is unreal. I don't know for some reason it doesn't feel real but I know I'd be torn apart if she leaves.

Whoa... slow down is my advice. You only just met and hung out twice. You don't know this girl at all yet. Take your time to truly get to know her. She may not be what you imagine her to be.

Thank you. You're very right.

Also… be wary. Anyone who declares strong feelings after 1 or 2 meetings is trying to rush things too quickly. There's a reason for that, and usually it's neediness or desperation. Then she backs off a bit. That’s contradictory. You may get more of the same behavior from her - and anything else that comes along with it.

Did you meet in person, or is this all online? Cuz this sounds very similar to a catfish scheme.

They hang out.

Whatever you might feel, don’t do anything that may seem you are over heels. Take your time.

When you say that it takes her a time to respond to your messages, how long we are talking about?

I know thats what he said. But it was just one word in a long post. Thats what put my guard up. No description of any activities.

Hello,
Thank you for sharing your story here, it means that you trust this forum, and it means that you seek help here,
I have just read your post, the conclusion I came out with, is that your are tormented,..
I'm not going to dive in how u met that girl, and how fast you liked each other and what made her FEELINGS change in one day and night after only one hang out meeting each other.
I'm not being ironic here neither I'm mocking on u, u are too young and she's younger, and ur body is discovering and still growing, u got so much to pass by and to experience.
I'm going to jump directly to the main point when u said:" how do I stop letting this taking so much effect on me, I want to feel okay if things won't work out...".
Take it from me: Don't build high expectations from this relationship, all the catastrophe in our lives was in being excessive, was in going too far, going too far in love going too far in feelings, in hope, in expectations...
What comes fast goes away faster...
I know u feel stuck, alone, can't do anything without her, everything depends on her, ur happiness depends on her, every happiness depends on something or someone isn't true, and if it is true it is temporary.
U got hurt in ur pride, and in ur masculinity and u think something is wrong with u made her leave, and the story isn't like that, you and her your brain chemistry didn't fit with each other, nothing's wrong with you.
Look! I'm going to be quick and lucid and hope u catch up with me.

There is a genius solution that you need to know, and this solution consists on two marvellous tricks:
1)-The art of letting go.
2)-The law of getting used.
they complete each other like day and night, you would never imagine what can an art and law do when they are mixed together! Miracles!
The art of letting go it is voluntary, and the law of getthing used it is an instinct that is combined in the subconscious, but u can't reach it unless u be open to practice the art of letting go, of forgetting, you have to prepare for it, if you give allowance to
your mind and to your spirit to elaborate the road to it. Then u will be able to get used of living without her,
I know u will get used it is a survival basic instinct installed deep in you, and once u get used of her absence u will be okay, free and happy, you will forget about her by time, slowly...little by little...It's like sleeping!!... you don't know when it comes! neither you know the worlds you would be getting through, then suddenly you wake up with the sunlight wondering when you passed out!!.

Hi,

Your story reminds me of when I began to go out with my then-boyfriend(today-husband). I was 19, he was 20.
I have always felt things more strongly than he did, waiting at my window 30 minutes before our meeting, having him on my mind every single moment. I felt upset whenever something disturbed our dates : calls, delays....
When we married 7 years after dating, I realized that I did not know him that well because I was all the time blinded by my eagerness to be with him.
You are just in the beginning of a relationship, it is okay to want to live beautiful things but keep in mind the most important thing is to know each other sufficiently so you won't make mistakes.
So take a step back, live your life as usual when she is not with you, enjoy the time you spend with her, and the most important thing, let your heart and your mind work together when you take decisions. Especially if you are meeting only online right now.
I hope the best for you,
Mittrei

Have someone noticed that there’s no need to post here since the OP doesn’t reply. 🙄
Your time is gold.

The absent has his/her excuse till he/she appears,
Most of the replys here in this forum havent been reacted yet, even haven't been seen, the important thing is to make from this great forum a field of getting experiences for the other users. All the stories are same in the context they all share the same pain. They all seek the same purpose, the salvation!