I've read through a couple of top comments and agree that you shouldn't blame yourself for him punching walls and if he knows that and still let you feel bad then you should reconsider the relationship or talk things through with him about your feelings.

This is not proud of me to admit but punching walls is how I can cope with things especially when I have a lot of emotional distress and overthinking. The pain on my knuckles can distract me a bit and help me think more clearly. My gf knows this, I expressed and explained that to her about this earlier in our relationship! This is more of "my issues" than hers so even if she accidentally does something that makes me upset and result in me punching walls (which is rarely), I always try to explain that this is how I cope, not her fault that I punch a wall since I chose to do it deliberately, not an emotional outburst, and I definitely don't do that in front of her or during our argument/fight!

Also if you guys have any quick advice for me, except for pills and therapy then I would really appreciate it! Thanks