I think it's important to stay focused on the facts. This is a highly emotional time and I'm sorry you are having to go through this.
Yes, I am sure he is sad and lonely (and I'm sorry he is) but the facts are:
He lost job, insurance, etc. and stayed out drinking for days. I called cops for a wellness check (he was in a park), they brought him to ER, he went through a 10 day detox and is now in a sober living house.
Mental health issues are a big factor in alcoholism, no doubt and so it's easy to have compassion and empathy at times and that's not wrong. That said, you have yourself and your child to look out for. Ideally your AH would be looking out for all of you too.
This, in my opinion, is where you need to take the focus off him and put it on to you and your child (yes, easier said than done). There are big things going on in his life but, especially, with him losing his job etc your responsibilities have grown and that is where your focus needs to be.
Your boundaries are not wrong. While there is no need to punish him (which seems to be his take on this, I don't see that) there is a real need to stay focused on yourself.