I've been there when it comes to dealing with a shitty roommate. My first roommate in the first college I was at was nothing but a complete lying asshole of a jock. I like my video games, cause well, games are fun. But he would tell a couple neighbors that I didn't do anything but that and it really annoyed him..instead of coming to me (mind you I had a gf who kept me in her room for a week straight for nothing but sexy times, and sometimes including her roommate too). Now I brought the 360 and he brought the PS2 for his sports games, but the moment he gets a kingdom hearts game, he played that more than I was on any game combined. A lot, lot, worse happened which is why I can understand and be sympathetic about your post.
All I can really say for advice is just stay who you are. It's not worth it trying to waste your life away being somebody you're not for the sake of others, as that roommate of yours was doing. Also remember, no matter what people call you, that's not important. What's important is what you allow yourself to respond to. It's not what has happened to you that defines you, It's what you have made it through that truly defines your character.
Best of luck on your next experiences. If you can get into that better school, maybe it's what YOU deserve. Not just because of your ex-roommate and the drama, but because down the line, maybe you won't get a job because you didn't go to a better school. You never know, so take what life offers to the fullest.
Life is like a grindstone: either it wears you down or it will polish you into a fine jewel. Do what you will, but be yourself through it all.