I'm so sorry you're having to manage all this stress on your own. I understand the feelings of resentment. I too thought many times when my exah would resign from his job and enter IOP how unfair it all felt. Why is it I was always having to be responsible and he gets to walk away from the mess he creates and start all over.
Life just isn't fair. Sometimes that quote is a lot easier to swallow than others, I know. Ultimately, you have to make the best decisions you can for you and your son. I agree, a meeting will make you feel infinitely better. Truthfully, you may never be able to lean on your agf in the way you would a partner who isn't an addict. She may always be unreliable. I'm not saying that's a foregone conclusion, but that is a possibility, and it's something you may want to consider.
I wish you the best, and will pray for you and your son! It's a difficult path being a single parent...but I've found, one day at a time is easiest. Tomorrow will take care of itself.