I’m really sorry you’re going through this. This is rough and I hope you and your wife both find a way through this.

Some thoughts from an internet stranger:

1. Your ADHD is not your fault. You mentioned not doing anything about it for around a year: please remember that ADHD affects your executive function. Maybe you feel like you could have done something earlier, but that’s part of the cruelty of executive dysfunction: we rationalise the inactivity (“I was lazy”, “I couldn’t be bothered”, etc.) because that’s easier to understand than accepting that for whatever reason your brain just couldn’t go there. You’re doing something now and that’s what matters.

2. Just because your relationship feels like it’s not good now, that doesn’t mean it can’t improve. It sounds like both of you are carrying a lot, and maybe for now the right thing is having space from each other. That’s sad, and feeling those feelings is valid and important. But that doesn’t mean the story is over for the both of you. Some other people here have mentioned couples therapy, and if that’s something you’re both interested in I’d also like to join in with recommending that.