Your H is co-dependent, he thinks he is responsible for how his parents feel. He doesn't know where he stops and they start. Solution - teach him by modeling healthy boundaries. This will be good for you.
You two do a lot of mind-reading I bet. "You think____________." Since you didn't communicate well you fill in the blanks. Solution - be very clear about what you think and feel. Harville Hendrix has some good examples on healthy dialouge.
"H I am not out to get anything more in a D then what the law allows. This wasn't my idea but I am surely going to look out for myself."
Boundary and let's him know what you are thinking.
It sounds like your H was attracted to you because you are the opposite of his Mom - independent, low maintenance, interesting etc. Have you tried getting him to help you with something? I get the impression that he was taken care of too much.
What are your goals?
What are you grateful for?
How are you taking care of yourself?
Who have you helped today?
Cheers Coach
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.