Feeling a bit frustrated

A few years ago my husband was diagnosed as diabetes II. He wound up in the hospital in and out for 3 weeks due to an infection that didn't go completely away the first time. Anyway, he came home and we slowly adjusted to life with him being home.

Fast forward to 6 months later, he started getting grumpy again. (about 10yrs ago we had major issues with him getting upset). It was frustrating because I really didn't want to go through that again. After awhile I think he realized what was happening and when he'd be in a mood, he would disappear upstairs for awhile. When he would reappear, we would try and pretend everything was ok.  He then later told me that when he's having these issues, he can feel himself getting upset, but really can't stop it from happening.  So when he has a grumpy time, I try and breath and not let it get to me. It's hard not at times because it's like he doesn't really care how he speaks or acts with people, especially myself and the girls. I am trying to be understanding, but not easy.