Is there anything you can do to help get rid of the feeling of being insecure?

I'm a teenager and for about a year and a half I have been very insecure about my friends. I can not exactly explain why. At first I thought it was because I was leaving school and was worried about loosing all my friends. But to tha day it continues and have now finished my first year at college. At first I would be worried that my friends have fallen out with me everyday, and this would make me cry, and id have no appotite. This would happen everyday. As tome goes on, it becomes leas frequent, but it still occurs. I have a boyfriend, and it effects our relationship as I'm constantly doing thins for others, and not for myself or us. I juat wanted to know if I should go on anti-depressants as depression is the closet thing to what I feel. Help is much appreciated as I've been suffering for so long. And I just don't know what to do.