Overreaction to simple things

hi, i dont even know where to start.

I overreact to the simplest things, for starters, and then i get angry at myself for overreacting in a downward spiral which usually ends with me on the floor wondering how i got there or punching the hell out of some wall. I dont know if this is at all related, but i have no self confidence, for example, I can check my schedule and put it away, and then although i know what class I have i'll be unsure and take it out and check it again. I have no real friends, like no one i can really talk too, and when I try to talk to my parents they just give me that look, like... well... the think im just trying to get attention. Once i asked one of my "friends", and he called me an immature brat and said i was just trying to get attention and the next day started a rumor that I was gay. Since then ive moved to high school and havent asked anyone else what to do.
anyway back to the issue.
when i get overreact to things it just feels like everything is against me, for example today i was having trouble with an essay and ended up hitting a granite wall and i dont think my hand is broken but when i went back to my desk i put my feet up on a little shelf like i always do and it snapped off the brackets. My parents thought that I had broken it intentionally so the sent me to my room, not as soon as i walked in the door than the electrical outlet exploded in sparks luckily not causing fire. the electrical surge blew out my lamp, so i had to sit in darkness with myself. Basically the universe hates me and im finding that I hate myself too. I just feel like crap all the time, i heard st johns wort can fix that but i cant grow any or buy it without my parents knowing. IS THERE ANYTHING THAT I CAN DO??
please help me im really desperate.

by the way im just 14 years old so dont have much freedom as to what I can do.