Life going downhill, please help?

Well curently I'm a junior in high school and I'm usually the over achiever but now I feel like giving up. I used to love school when I was a freshman, although I was ugly and immature I had so many friends and I never worried. Sophore year was sucky and so far this year is the worst. I recently started taking college credit classes and so I have to drop football and a lot of clubs just to study. I always helped my friends with whatever they needed whether it's advice or not, to repay me they leave me out of everything. Everyone is so harsh to me, and I mean EVERYONE, like I did something wrong. Everytime I try to talk to someone they just ignore me of get mad even my so called friends. I have so much problems outside of school as well and people still treat me badly when they don't know what I go through. I know I'm not very attractive but people don't have to be so mean. It hurts me because I see everyone laughing and having a good time but I have to sit and watch.my school is full of assholes even the teachers who only respect the varsity football starters. I can't seem to make any new friends. I also have really bad anxiety that is getting worse, I am always shaking even when I'm not scared, it's like my mind is always worried. I'm sorry this was long I just need some tips or advice to get me through because for the first time every I just feel like giving up, like life just really hates me. Thanks