Whiff, I fully understand how you, and any other woman who has lost a husband, must feel. I do also think that most of us, at some point become annoyed with them, for whatever reasons, and likewise I'm sure they feel the same way about us wives too!
I think it sounds like the OP is getting totally worn out herself, and probably feels a bit of annoyance towards her husband for not being able to help her out with all the daily chores. It's hard for anyone, but especially those who are working full time.
I think OP needs to take a deep breath, appreciate that her husband has an illness which makes him feel exhausted, but also start to think about her own well-being as well. It won't do anyone any good if she becomes worn out and ill.
Mel1967, talk honestly to your husband, and tell him that you understand what he's going through, but also tell him that you're finding having to deal with all the chores yourself, as well as working full-time, is wearing you out, and you need help. Cut costs elsewhere, but find the extra money for a cleaner once a week, and someone to do your ironing. You won't be any good to your husband if you find yourself ill through exhaustion. Be kind to yourself.