Your options have narrowed a bit. Great!
It was around the time of life you are now experiencing that I became aware of shutting off certain possibilities basically forever. If you don’t go to medical school now, you probably won’t. It’s too late to be a fighter pilot; your ballerina ship sailed long ago.
In reality, most of those options still exist. Some people go to medical school in their thirties and beyond. Those options just have a higher price. Switching “careers” when you’re 23 is nothing; doing it at 45 is often perceived as something akin to a painful divorce and remarriage.
But closing down options is just fine. Most people in the world don’t have those kind of options in the first place; being able to “be anything you set your mind to” is not a natural state of humanity. Too many options can cause paralysis.
You live in a very privileged nation. (From your spelling, probably Canada, the UK, or Australia, in which case you may also enjoy free dental care!) Your options are narrowing from “more things than you could ever think about” to “a fuckload of things”! It feels weird, but it actually makes your life much more manageable.
Treat terror like PMS
PMS is a thing that happens to you. It’s separate from you. You’re not a “PMS-haver”; you’re a person with a temporary and annoying condition.
Similarly, do not think of yourself as “terrified,” as though that is somehow part of you. Surely, you’re not terrified 24/7. At some moments, you are crippled by fear, but at other moments, you are eating cereal.
So, think of yourself as someone who periodically has bouts of this annoying condition called “terror.” How long does a bout of terror actually last? Fifteen minutes?
When you have the experience of terror, separate it from yourself: Oh look, terror has come to visit me. Roll your eyes: how annoying! Say calmly to someone, “Oh, how annoying. I’m having terror symptoms again,” as though you were reporting on a fresh pimple or the first sign of menstrual cramps. Hell, maybe take some Midol and hope for a placebo effect.
And then get back to work.
Most of the things you’re worried about don’t kill you or put you in jail. Also, no matter how your early twenties go, you can always explain them away (I was young and stupid! Oh, my wild and crazy youth!), because, while 21 seems old to you, to other people, it’s basically still childhood but with sex. No one over 35 thinks people are really all that responsible for what they did at 21.
When entering the adult world, it’s hard to think about everything at once. Fortunately, in your early twenties, people think it’s cute if you live in an apartment with no furniture. One thing at a time. Also, keep in mind that many of the adults around you are actually getting a little dumber every year they’re out of school, so you have some advantages. (See Bullish: Using Your College Skills to Succeed After College.)
Good luck! Everything’s fine. Everything’s going to be fine.