He spends money compulsively. For example, he decided that he wanted to start dressing more formally for work (there's no dress code and he had been teaching for years in jeans or khakis). So he went out and bought (I'm not kidding) probably 25 suits and 100 ties. Very expensive.

Then he decided that he wanted to learn more about art and literature. So, every day (again I'm not kidding) 10 to 12 packages would arrive from Amazon, loaded with expensive books, most of which he never read and which are now lying on the floor, because he can't decide how to organize them.

Sorry if I missed this already but it sounds like your H is BiPolar. He appears very depressed for a time and then his mood swings to manic behavior, such as the complusive spending habits. 25 suits and 100 ties? That's not "normal".
Of course the real question is, if you are not even M to him anymore, WHY ARE YOU PAYING FOR ALL OF THIS DEBT?
The two of you as a couple seem to feed off each other's dysfunctions. He knows you will enable his behavior (get him out of trouble). This probably also gives you some sense of being needed that you crave even though your self-esteem must be in the crapper for putting up with this man.
Your story frustrates me to no end. As does Chrissy's and some others. It just makes me sad and perplexed that women get stuck in these ABUSIVE R. And it's not just women. Some of the men on this board do the same thing.
You seem like a very intelligent and interesting woman. You deserve better. That's my 2 cents.