Hey vincentvega,
First off, I want to say that there is hope! If you've ever read "The Hitchhiker's Guide to the Galaxy", this is where I say, "DON'T PANIC

" in big friendly letters, since that is precisely what you need to do. No matter how far down a bad path you've gone, you can get back to your old life with time. If you want to hear my story, keep reading. But if you just want to get to the good stuff (how to get better), skip past the block.
--------------------------------------------------------------------------
How do I know? Well about 5 months ago I went through a really tough experience on an LSD analog that left me shaken, weak, questioning my sanity, and just a bit damaged. The only reason I got through it for a while was my school work, which took up most of my time and thought.
However, things started to go downhill during finals week when I smoked some weed (I'm not ashamed to admit being an avid pot enthusiast at UCSC all of last year

) and had a huge panic attack, exactly the same as you described.
To fast-forward, after finals were over (the panic attack really shook me, but I somehow passed my classes with solid grades) and I came home, I felt different. I was empty, spaced all the time, and just a lot dopier in general. I didn't want to do ANYTHING and smoking weed gave me the opposite reactions that I was used to. I quit the drug for a couple weeks to find a job, but without the drug I barely felt any better. In fact, quitting just left me even more spaced and dumb, which left me depressed. All I could think about is how terrible it was to feel so dopey. And then I got meningitis.
Meningitis broke me, in mind and spirit. It made me unable to think anything for two weeks and took away all energy that I had left. My outlook on life dipped drastically, and in addition to the exact symptoms you gave in the forum (you're not alone here , the future looked awful, and I actually even contemplated ending it all at my worst

. I'm not sure what kept me going, but I'm glad something or someone did because I'M GETTING THROUGH IT.
After (and even a little during) my two weeks of viral meningitis, I found work and started to occupy my time. I hated it so much, and at the time thought it was only making things worse. However, now I see that it gave me a distraction from thinking about myself, how I'd never get better, and stress about something other than myself.
A few weeks later, I still felt pretty terrible and saw myself spiraling down more and more every day. Being unable to talk to others and not having the energy to both work and recover, I almost gave up again. I had forgotten what it felt like to feel, to have fun, to look forward to anything. So in my miserable state, I turned to solving the symptoms of meningitis, mistakenly thinking all this was caused by that disease. Still, a doctor recommended acupuncture so I tried it out.
Acupuncture is the way to go; it's the way out of the ditch our lives have been in. I'm currently three weeks in and feeling loads better, almost even like my old self. I just started sleep hypnosis as well which is helping me heal and deal with my issues at a deeper level. Now here's the important part for you:
--------------------------------------------------------------------------
You do not have schizophrenia. You are not insane. Something happened when you had that panic attack in your mind, and while you're feeling crushing anxiety and depersonalization on a massive scale, I honestly have no clue what's causing it in both of us. HOWEVER, I've learned how to start to get over it because I got lucky:
Step 1: Kick my favorite bad habit for a while.
I love smoking kush more than most people, but every time we smoke it, we get the polar opposite effects from what it should do for us. I've been smoking on and off these past few months, but now I'm done until I feel 100%.
Step 2: Receive alternative medicine and DRINK GINSENG TEA.
Our illness is not physical, it is mental. Xanax and other anti-anxiety/depression meds might help, but I chose to get acupuncture and meditate instead. Hypnosis can help too, along with a long list of other treatments. The important thing is we cannot consciously deal with the issue that's always on our minds, so we need to learn to relax without smoking and let our subconscious deal with healing. As for ginseng, American Ginseng contains ginsenosides that calm the mind and help with insomnia, as well as promoting strength and recovery. I doubted any of this would work from the start, but the results don't lie; give it a try

.
Step 3: Distract yourself.
Ideally, do something you love doing that is low-stress. This will help you adjust back into normal life and become strong again. I've been running daily, which pushes me to my limits, which you need to rediscover. New and lower limits are meant to be tried and pushed until you reach and (ideally even surpass) your old ones.
Step 4: Socialize.
You're a 20 year-old and should be out in the world having fun. You say you can't have fun or look forward to anything, but the only way to get over that is to go out into the world and go to a concert, drink (LIGHTLY) at a party, meet new people, jam with a band, go explore somewhere new, or just pick up online gaming. Don't over-stress yourself, but try your best to have fun doing things you used to love. I went to Outside Lands this year and the first day or two, all I could think about was how I used to love this stuff, but couldn't anymore and how people must think I've got some issue for being so lethargic. The third day in, I felt better and you've really got to stick with trying to have fun to enjoy life again.
Step 5: Give it time.
Recovery from this...thing can't happen in a day. Every day I wake up a little better, but only a little. Try to maintain a positive outlook on the future, even if you can't picture a bright one. Make plans, don't stress if you can't keep them, but certainly do your best. What did you always want to do with your life? Regain interest in that, whatever it is, and keep your chin up. Things will get better, but the most important thing to take away is you will get better, and you will have grown from the turd that life threw at you. Get sleep every night, and get DEEP sleep every night. Listen to sleep hypnosis tracks while you try to sleep at night, every night.
I hope any of this helped. Stay strong and keep swimming man, life gets better. I know how terrible what you're going through is, so hit me up if you've got any more questions and I'll see if I can help. Best of luck to you, and give whatever you can a try if you're still feeling down after a year.
--------------------------------------------------------------------------
Stopping by Woods on a Snowy Evening
Whose woods these are I think I know.
His house is in the village, though;
He will not see me stopping here
To watch his woods fill up with snow.
My little horse must think it queer
To stop without a farmhouse near
Between the woods and frozen lake
The darkest evening of the year.
He gives his harness bells a shake
To ask if there is some mistake.
The only other sound's the sweep
Of easy wind and downy flake.
The woods are lovely, dark, and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep.
-Robert Frost