Unfortunately, there isn’t anything you can do until he wants or accepts help. In fact, the more you push when he resists, the deeper he will go into that space of denial and resistance.
Your best course in the present situation is to focus on taking care of yourself. You’re prepared when he’s ready.
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism