Medication may or may not help. He needs to consult a professional. That said, his having ADHD is no excuse for verbal and emotional abuse. If you continue subjecting yourself to his behavior, you will completely lose yourself and your mind.
Take it from someone who knows.
I was married to a narcissistic manipulative and abusive man. We were married for 17 years.
He did not have ADHD.
I ended up a shadow of my former self walking on eggshells daily afraid to set him off. No way to live. And I was afraid that our children would be affected by it. He alienated me from my family, so I had no support. I would urge you to speak with someone as well. A counselor… About what you were going through. Your mental and physical well-being are important.
I’m engaged to a man with ADHD. We have been together going on 5 years now. He’s not abusive to me in any way emotionally verbally, none of it. ADHD does not mean the person is going to be abusive. There may be something else going on here. He might have a comorbid condition.
And because you mentioned that he will not get help until summer. I don’t think you can wait until then and I don’t think you should you need to leave. At least for now.