Take a look at Rejection Sensitive Dysphoria (RSD). It’s common with ADHD and can explain how he’s gotten into this cycle. There is a particular medication that can help with RSD, as well as therapy/counseling.
Of course, if he isn’t open to accepting his behavior and wanting to change, nothing you do or say will make a difference.
Penny
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism