Deb,
I'm so sorry to hear that you're feeling so down. It's good to know that you have someone there who really loves you, it's a very big help. She knows about your condition and loves you for you. Please take her advice and find some therapy? Are you on medications? Maybe seeing your psych for a meds review would be a good idea if your feeling so bad. Are you both working or just her? I think 13 hours a day is too much for anyone, let alone someone with a MI. I know working is important for financial reasons and for self esteem but working like that is going to make you and her break down very soon. I think you need to take it easier for your own health's sake. Can you see a public counsellor if you have them in the UK? If not, can you join a health fund that will cover therapy? Also try to find support groups, they are very understanding and should be able to help you recover. Also try this website
www.moodgym.anu.edu.au it's pretty good. It's no substitute for professional counselling but it does teaches coping skills to prevent you from becoming more depressed. I got referred to it by a psychologist and I thought it was very useful.
Hugs to you hun,
Nathan xo