How to approach partner about anger management

Very short back story, I have posted quite a few times of anyone wants more info. My partner, working towards real recovery for about 6 months, had a small slip the day before Valentines day. It was 2 weeks after my birthday which was a disaster(I felt slighted and didn't respond well and in return he didn't have empathy) The slip led to full enforcement of my boundaries, which right now is space, low contact during the workday and separate sleeping, zero intimacy. He has always had a fairly bad temper, accompanied with negative attitudes and excessive complaining when things don't go his way. He knows it is an issue and has said he will work on it. Since the slip things have gotten worse, seemingly after he also admitted he has a HUGE problem with escapism(currently using YouTube, nothing inappropriate) now it seems that has been replaced by being angry about everything. I believe it comes from a deep-seated entitlement issue and low self esteem. I really don't know how to approach this subject with him. I'm afraid he will feel so defeated knowing there is something else he needs to work on for the relationship to continue. But I no longer feel safe putting so much into the relationship. Does anyone have any input or experience with an angry partner?