Friend or foe help me please need to no soon?

Recently most of my questions asked is about my friends and my looks, there's this one girl who gets on my nerves so much (Lucy) she called me retarded and my best friend backed her up :( i felt so upset and started crying. I have a boy friend and he is soon leaving the school when Lucy found out she instantly started to go on about how he's going to dump me soon, while my best friend just goes on about how my boyfriend is a geek. I just get so upset and want to find more friends who don't put me down. The only other girls in my year are the popular girls mostly we get on well but when I am around them i get so nervous... What would you do if you were me?