Late Blooming Anxiety

This is my first post on here, so sorry if it's a little rough.
For a few months I've been dealing with bad bouts of feeling antisocial and not really wanting to immerse myself in large social scenes. This is a little weird for me considering how social I was in high school and my freshman year of college. In high school I had tons of friends, was always up to meeting new people and seeing new things, had a wonderful gift of gab, teemed with confidence, and dated some of the coolest and prettiest girls at my school. During my freshman year of college, I was able to assimilate myself pretty well. I only knew a few people from my high school that were attending the same college, but I made new friends pretty easily and got into the party scenes and the big social gatherings that were popular around campus. Fast forward to the present day and everything has pretty much been flipped. Most days I just want to hang out in my apartment and just dork around on my computer or play video games. I've kinda narrowed down my circle of friends and consistently hang out with only a few of the same friends I had from last year. Sometimes, I try to avoid social settings in fear that I'll be really awkward and just come off as weird. Earlier I mentioned I had a gift of gab - that gift is long gone. I absolutely suck at small talk now. I just got a new job, and I'm getting to know some of my co-workers better, who I think are really nice and pretty funny, but I feel as if I don't contribute anything to the environment. When I talk to people my side of the conversation is filled with one word responses and stereotypical small talk. And don't even ask about girls right now I can barely approach and talk to people I view as seemingly normal, average Joe's so I don't even bother approaching girls that I think are cute. Along with all this, my general lifestyle habits have gotten worse. During the summer, my best friend and I worked out and exercised together 3 to 5 days a week. Now I barely exercise, my nutrition sucks, and I've lost something like 20 pounds (not good considering I'm not overweight and don't have that much muscle mass). I have a hard time falling asleep before 2 AM, and I just feel drained and tired every breathing moment. A lot has happened in my life off campus all the way back home that I feel has caused some general anxiety, and perhaps is starting to take effect on my social life. I'm just looking for any tips for coping with anxiety so I can get back to living how I used to live. I'm pretty tired of always feeling awkward and aloof. I feel like the entire social aspect of my life is currently pretty unfulfilling.

Yeah, social anxiety weighs quite heavily on me as well. Meditative practises can help with that, combined with a "bleh, who cares" type of attitude.

I have a good friend who is like you. Never understood why such a happy extrovert character has guilts and feels bad and shy. You see, some problems with emotions does't come from friends and social environment, but from the start of our life, our parents and something push them out a certain time in our lifes
I don't believe that a change like that in you has just happened, except if something really shocking happened that changed you. It must have been there all along.
From the other side, to have social anxiety is to feel threatened by other people. It seems that you just compare your early life with the Now.
All i can say is that you should keep it real. Give it a try to push yourself to try something new and experiment with your life.