This is all one big post:
"How do I stop being so compassionate?"
Stop calling what you want to do when you feel like giving in to his bad behavior "compassion".
It isn't compassion.
It is co-dependence. It is trying to fix someone else. It is anticipating and guessing what is going on in his head, as if you had a psychic line into what he thinks. It is thinking that YOU know better than he what will fix him.
It is arrogance. We do not get to live THEIR lives, even though we think we have the right to dissuade them from "the error of their ways" or protect them from what we see as their next mistaken step.
When I was married to my now ex alcoholic abusive husband, I thought that I knew what was best for him. I violated the boundaries of what was him and what was me, and I thought I knew best what would help him.
I was wrong. It took me a long time to recognize that I was being arrogant, and it was not okay for me to step into his world and re-organize it so it fit what I thought it should be.
It was - and is - my ex husband's right to life an independent life, as HE sees fit. He is an adult. He has the right to choose to live however he wants to, and he has the right and the obligation to face the consequences of his choices without my intervention, manipulation, or direction. What I think will be his salvation - my prescription for his behavior - is merely my head trip into his life.
This may sound harsh, but for me, it was the beginning of separating myself from the intermeshed kind of joint "personality" we had become, where I watched out for what I thought he needed and saw life from his perspective more than I did from my own.
This, to me, is the beginning of freedom. Said with great empathy, take what you want and leave the rest.