Drunk people send erratic texts. That's par for the course.
You can't save him. He's going to have to figure this out on his own - I'd say that as a female, I would stay way clear of this. He's still married (?) and he may have gotten the wrong idea about your interest in him. When and if he ever wants help, he will find plenty.
I would ask, what do you think you are going to be able to do? Alcoholics will take down anyone within reach. Don't let it be you.