Second this: "You’re doing great"
And on top of it, you sound as though you now KNOW that you’re doing great!
It is normal for you also to be sad at the same time, because you genuinely cared for and probably still care for him.
You have already been incredibly kind and patient. He does not "deserve" better from outside of himself, he needs to create his own "better" by working on himself. Nobody else can do it for him or give it to him. He needs to create it for himself, or he will be forever stuck.
YOU, on the other hand, clearly deserve better, and you have taken the most difficult steps in that direction, so you are no longer stuck. You will find your "better", either "on your own" with your DC and broader community, or, in due course, if you want one, with a new partner.