I think i might be getting anorexia :S?

hey im tasha, for a few months now i have been trying too loose wieght i went on a pro ana site and now i just dont want too eat i feel the need too purge and i starv my self for a few days but i just end up eating loads of crapy foods after a while.i dont intend too be anorexic, but i have wild changes of heart and i dunno what too do. im 5'1 and i weigh 10 stone, alot of people in my family have had anorexic, i dont want too suffer but tbh i just cant help myself can anybody help me !?