Hi, LilithOwl; I'm not going to say I'm the best at giving advice on this (house ridden because of my anxiety) BUT when I do have to go out, I try to block out all my thoughts with a couple things: music, activities and a run through of the things I need to get done vs the things that could happen. Focus on the RIGHT NOW; I like to cake on makeup so that takes my head off a lot of things; you probably don't need to do that, but you get the idea.
I don't want to get too much into your life but... do you think your boyfriend thinks your lame or does he really? If he does, that's just adding coals to the fire. You need to be around people that are positive in your life; he's only hurting your chances of getting better if he's jerk. Also, if you've been evaluated already, it might be time to sit down with your parents if you haven't already and explain you condition to them. Then...if you're concerned about your teacher's thoughts....you might want to speak to him/her after class and explain the situation, s/he might be able to make accommodations.
It's the year of LilithOwl, don't let others hold you back from getting well and the life you deserve. On that note; I'm so jealous! I'm assuming you've made it to college and can drive! You're really going to go far!