Yes, I know. Contradictory, right?
But I literally have no choice. I'm on a bazillion and a half scholarships, which means I don't have money to pay double to room by myself. Hell, even ramen was expensive for me at some point during winter semester of freshman year - I was buying the off-brand, no-name, expensive-for-no-reason-because-it-tastes-like-burnt-grass stuff.
So how do you choose a roommate if you're slightly on the antisocial side of the spectrum? You don't.
Actually, you do... kinda.
If your university allows you to pick your own roommate, ask around and see if any of your (FEW!) friends needs one. If one of them says yes, there you go. You're saved from having a horrible roommate situation.
Well, hopefully. I know some people who roomed with one of their friends and swore to God they'd never do it again.
If your university, for some inhumane reason, DOESN'T allow you to choose your own roommate, the first thing to do is sit in a corner and cry, then wipe your tears and shake it off.
The next best thing to do is to grab a notebook and a pen, or a pencil if you're a constant mistake-maker like me (no, seriously. I could MAKE sheets of paper out of the amounts of White-Out tape I've used in my lifetime).
OK, now that you've got school supplies in front of you, use it to make a list of things that a roommate could do that would piss you off.
You've got a few options here:
1. If your list is ridiculously long, take a second and third and 57th look at the issues you wrote down, and make sure that those issues are actually things to get bent out of shape for - if you're not sure, ask your friends and family what they think.
Also, ask yourself, "Should I really be mad about this, or is this mayyyybe not such a big deal?"
2. Use your sensational ability to imagine scenarios that have a 0.00000001% chance of happening to create a situation in which your roommate has done one of the things on your list. If there's no one in your house - because who needs to be seen shouting at nothing - physically act out the scene.
Pretend that your roommate is standing right in front of you. Really get into it; feel the anger.
Blow up at the air exactly like you would if you were going off on your roommate. Felt good, right?
Saying everything that's on your mind and not getting in trouble for it? OK. Now that you've done that, take a deep breath and sit back down.
Now, evaluate your response and think of what you could've done differently, if anything. Was there something you said that probably shouldn't have been said? Could you have been calmer about the situation? Was it really something to go off on your roommate for?
Write down a few different ways to handle the situation in case it does happen. That way, you're prepared (hopefully) for anything your roommate could throw at you.
3. If you know your anger has a tendency to flare up, practice some breathing techniques, like the 4-7-8 (inhale for four seconds, hold it for seven, exhale for eight).
There's also several meditation and relaxation apps to choose from if you feel that helps you.
And if all else fails, just avoid your room like the plague.