Problems with my mom... Help? Please?!?

Ok, I'ma make this as short as I can.. My mom is a control freak. She flips out on me for every little thing. If I make a tiny mistake like, I forget to put a dish in the dishwasher, she tweaks! And If I say sorry, she yells at me for saying sorry. I'm 14 years old. ALL my friends wear bikinis, and she started buying me them 3 years ago. But now, it's a problem for her? And no, I'm not overweight, I'm actually pretty skinny (but muscular) There's a pool party in a few days & I wanna go but she won't let me cuz I wanna wear the bikini SHE bought me. I tried to say I'll wear shorts as bottoms but she sent me to my room... I have to be in at 10:00 on weekends & my friends are out til 11, I hate this. Please, help me out! Thanks.