I feel so stupid for even caring what is going on with him after all the damage he's done to our family.
You know, just because someone is behaving poorly doesn't necessarily mean you stop caring about that person, especially when that someone is a spouse. I believe it's perfectly normal to experience the conflicting emotions you describe.
At the end of the day, your AH is sick. And not only has he abandoned you, he's given himself permission to withdraw from everyday responsible life. In his world, there are no responsibilities. Just indulgence. The ultimate reason why you filed for divorce is because he's not playing by the same set of rules as you are. And you are justified in doing so.
Your feelings are your feelings. And while they'll be overwhelming at times, they won't kill you...