Self-confidence issues?

Ive always had issues with my self-confidence all through my school life so far I'm in year 9 going into year 10 soon but I still get bullied at times I've had 2 boys I've been out with that are In my class They basically used me I've been really low on self-confidence I've never liked my look,, I've got long brown hair polka eyes aparently an hour glass figure according to mum but I've never been too sure,, I've never liked myself,, could anyone give me tips on how to help? x