Feeling Guilty for my Caregiver

Hello,
I am a chronic (23year) migranuer(sp) and my husband, who was my boyfriend in the early years has been ridiculously supportive. When things got to the point where I could barely function he flat out told me to quit my job and worked his ass off to get a major promotion at his job. His job is now more stressful and more work and he takes care of most of the household responsibilities. We have two kids, one in college, one a junior in high school, so they are pretty self sufficient, but he tries to do as much as he can for them unless it's "mom stuff". It makes me feel so guilty. His parents are getting up there and call all the time because they need help and his sister is single and he does all her "husband" stuff too. I honestly don't know how he's still standing. When I get upset and cry, he gets upset with me and if I have a good day and do things around the house he gets upset because he says you're going to be in so much pain tomorrow, you should relax on those days.... you can pick one thing to do, like the dishes or one load of laundry. I worry that he secretly resents me, but he reminds me it was his idea to have me quit me job. Can some caregivers give me their HONEST thoughts? Much appreciated
Dana