Just found this thread after losing the last one, and glad to see it exists as an outlet for everyone going through this.
My DH has had depression for what he now thinks is about 2.5 years, it has been severe for a year, and it was diagnosed properly in November. Someone earlier said, probably even cancer is easier to deal with than this, well we got the double whammy of this depression kicking in after he was diagnosed with advanced prostate cancer - partly because obviously that is monumentally depressing, and partly because the treatment for this is a hormone suppressant that causes mood changes/depression in itself.
His depression has manifested in what has felt like a complete obsession with me, a large chunk of which is about him being convinced that I have had/am having/will have an affair. I cannot begin to emphasize how much that is not something I would ever do and indeed something I have never considered nor has it crossed my mind in our 14 years together. But his history of his first wife leaving him seems to dominate his feelings and gets projected onto me. He then tries to explain it by saying it's because I talk differently to my friends than I do to him, I live another life at work, I talk about other people etc. etc. etc. and for 8 months I took this as being all my fault and spent a lot of time and energy trying to be "better".
I started seeing a counsellor at the end of last year and now I don't blame myself but I feel a low level anger that there is no understanding for me while all I try to do is be understanding. I am also struggling to deal with his sudden unquenchable need for sex and every time I don't feel like it (because good god what about dealing with all of this is a turn on?) he goes off the deep end that I must be getting it somewhere else/I don't fancy him any more etc. It's a constant walking on eggshells situation, as so many people have said, and I am too afraid to think that we have lost a full year plus to this stupid situation when his lifespan is now almost certainly limited. What a waste.
I feel for all of you dealing with depression, especially those whose OHs won't acknowledge the problem or do anything about it, and those of you with kids which must add a whole new level of complexity.