I'm sorry it came to the point that you quit your job. Here's my question: If you didn't pick up the slack for him, who would have? Nobody? So those things would have just gone undone?
That is NO way to run a business, so I think the problem lies with the manager. She has had it too easy with you there working your butt off to make the place what it is.
Let's just see what happens after you are gone. Wait a few weeks and go back there and just see how it looks. I'm sure it will be a mess. Unless they find another person like you to do everything.
It's so sad that people who care are the ones that get crapped on in the end. I have a similar situation at my work, but it doesn't involve me. It's just ridiculous!
I have no doubt that with your work ethic you will find another job. Somewhere the deserves and appreciates you for the hard worker that you are.