Right there with ya on your 19yo. Currently, we have three foster kids in the house - one 19yo on suspended license (too many speeding tix), one 19yo with drinking citation, one 18yo with the same. H has been to court with kids three times in the last month.
FWIW - I think you are an astonishingly strong person. I often find myself wondering what you might accomplish on your own. Maybe your sitch doesn't quite fit but you are an excellent poster. We aren't that choosy about specifics. All of us are just trying to find our way through relationships.
Hang in there. I DO THINK you should buy yourself the occasional little treat. You don't owe sh!t to H - your combined income is half yours too.