Your post is full of "he" and "him".
What about you? What about your life, your future?
Who are you? Who do you want to be?
How do you achieve that?
This is the story of your life, not his.
Write the new story.
Waywards are selfish arseholes, and we're not.
The best thing about hitting rock bottom is that everything after that looks fucking fabulous
"Why did I care about what he was doing so much?"
And you will be able to focus on you. It takes awhile to get there, though, so take it one day at a time.