Hello friend. I have been where you are. I am 44 now, but around 19 or 20, I had the same stuff going on. I felt confident in high school, and somehow the same kind of worries you are having began happening to me. I was a successful college student, and working in a veterinary clinic. One day, I started thinking too hard about making eye contact w/a doctor, and realized I'd never thought about worrying about eye contact like that, and it became a thing for me. Around the same time, I experience a panic attack in a big lecture hall (it was a pretty claustrophic room, I'll admit, tiny movie theatre type seats, and I was by the wall with a big person on my other side). So I didn't know why I had panic, what that was, why I had eye contact problems, and from there I got to where interacting w/others and speaking up in meetings or class were not easy or many times possible.
The good part is that these symptoms often strike when we are young, college aged, even after being confident. YOU certainly have great abilities and talents, and they are still there. You are NOT your anxiety. It is just a thing and it will change, and you will learn how to manage it. I did sort it out, but I took the way of alcohol for a long time. For me, anxiety and depression became "one" and an antidepressant took care of all of it, although medication alone is not adequate. I know it sucks. Oh, and I swallowed a lot, just like you are saying. Just know you're not alone, and don't judge yourself. This is not about who you are. I promise it will get better, and you will get through it. Can you talk to a psych to help with the symptoms? And do you know of a good counselor? Many more people have these disorders than we know. I am glad you reached out. In 1994, the internet wasn't really active yet so I thought I was the only one...hugs to you!