Please don't feel that you are in the minority, and that most people are coping well with this. They are absolutely not - despite all the happy, smiley, leaflets that would have you believe otherwise.
I care for my Mum, so a different relationship, but I cannot put into words how utterly relentless, depressing and miserable it is. You are powerless to control it and have no idea when it will end.
All I can say is try and get some respite - be that a sitter, or a daycentre or club that your husband can attend unaccompanied.
I sincerely doubt that you will offend anyone here. We all understand those very dark thoughts, that would send the non-dementia world into apoplexy - because they really have no idea what this is like.
I would also recommend "The Selfish Pig's Guide to Caring", which will hoefully make you smile, and realise that you are not alone.