Relationships rarely happen when you expect them to, you won't hear any judgement from me regarding that. Infact they almost always come along at the least appropriate time.
it really sounds like your doing all the right things. I understand that " why me" sensation. You just want something simple and secure, yet it turns out to be more complex than you could imagine.
My partner s issues resulted in criminal behaviour and a spell in the jail. It took me a while to be sure, but he was patient and understanding and most importantly continued to look after himself while I thought about things. That went along way to proving to me he wasn't relying on me to maintain his stability. That he was being responsible for himself.
I like you have a lot of my own stuff going on,I knew I couldn't be a crutch for someone else.
Your man has proved he can be responsible with his health, and perhaps the security of the relationship caused him to let that slide. It's easy to do when your feeling good in your situation.
A gentle reminder that you aren't his carer, but his partner and that providing he takes steps to recover you are willing to work things out with him.
Explain your afraid because you don't understand, and ask if you can attend his mental health assessment/ pdoc so you can ask some questions. About his condition not to be invasive.
It can work out even with two crazies! ( how I describe me and my fella)
Only you know if your strong enough to tell him what you need a stick to it. Maybe a deadline might help.
Protect ing yourself to protect your son will never be selfish.
Be kind to yourself, and listen to your instincts, they will be the ultimate indicator of if you feel your doing the right thing.
Take care and I wish you both all the best.