Feeling a little down

Partly because it's hard to get enough sunshine in February, and partly because my husband has been irritable, I'm feeling a bit down. Husband alternates between feeling tired (napping for hours, not wanting to go anywhere) and being anxious. When he's anxious, he yells a lot - occasionally at me or at the dog, and often at his computer or some other uncooperative object. I wish I could just ignore this behavior, but often it makes me angry.

I don't know whether his diabetes makes him irritable or whether his anxiety is inherited. (His mother was highly anxious.) He says he doesn't feel well, has a headache most of the time. He has lost some of the feeling in his feet and his fingers tingle from the diabetes. Yet he still eats a lot of carbs, although he has started exercising more.

I don't want to be unsympathetic but he makes me upset.