Help balancing boundaries/frustration and love/warmth

Hello all! My husband and I have been married for 10 years, 2 young kids. He has ADHD. Refuses medication (says it makes him "really mean"), but does do hard work with a therapist. Some aspects of his functioning have greatly improved, but his contribution to our household is often times minimal and oftentimes a lot of drama, stress and chaos.

I'm having trouble protecting myself from those aspects that he brings to our family dynamic without at the same time being closed off to him emotionally. I cannot count on him for really anything and have had to take over most household/child tasks. Nothing he says he'll do gets done and he'll get upset if I remind him. For instance, he'll promise up and down to do something in the evening and then it'll inevitably get left to the next day. I've explained how this just puts more responsibility on me the next day (meaning then I do all the regular tasks while he finally completes the one), but it falls on deaf ears.

While I understand a lot of this is the ADHD, sometimes it feels like part of it is poor character. Maybe that's unfair? I feel bad for my kids that they don't have an engaged, warm dad. I compare us to the families in our lives and I feel so sad for my kids and myself. He's constantly on devices, but thinks that sitting next to someone while completely ignoring them counts as spending time together.

I don't know how to shield myself from his behavior and the resentment and stress it causes in me without disengaging too much.

He blew up at me today and was really mean, again. I'm tired of always being the one to extend an olive branch despite being yelled and cussed at and I just feel so overwhelmed. It flabbergasts me, but I feel like he's going to leave me. I want our family to stay intact, but I am starting to feel so burnt out