Self harm

So I used to self harm, but my boyfriend (who I've been with for over a year) would try to stop and help me. I never did it often, but lately Ive been having the temptation too... He says that if I give in he'll break up with me because he can't handle his girlfriend hurting herself.
 I've tried ways to relax myself, but I really need someone to talk to it about... I'm too scared to ask him cause last time he was worried and told his mum and my mum which caused drama. I've been to a pyschologist and I didn't enjoy it. 
What should I do?