I need some advice

I don’t really have anyone to talk to and I don’t think I could trust anyone with this so I was hoping someone on here could help me. Basically, I’m almost a month free of self harm and I’ve read some things of people saying it gets easier from here but I can hardly stop myself sometimes. It just gets so hard whenever I’m alone which is very often. I started self harming in seventh grade and I’ve stopped every once and a while but I always seem to start back up again.

I told my boyfriend I was self harming and he was so supportive but now when I do it again he gets so mad and it really hurts him. It makes sense because he feels like he’s not doing enough for me and I feel so guilty about it because he also struggles with his mental health. I just wish I knew how to stop myself sometimes because I want to do it so much in the moment but I regret it later. My boyfriend is the only one that knows about it but he gets really upset if I bring it up with him. I just don’t really know what to do at this point.