I don't know what to do, about two things!

[SaRawr!]

Hey people
well 1st thing
my ex wants to get back with me but i don't know weather i should or not becuase 1, everytime something happens between us one of us gets hurt and 2, i dont know if he would cheat on me again =/

the 2nd thing
im not really feeling myself atm, i feel fat, ugly and just generally useless. i don't know why but i want some advice on how i can forget about them

please help =)
Sarah xxx