Well first you have to be willing to forgive yourself. You didnt do anything wrong to get this desease, and it isnt your fault you have the problems you do. That said how you handle them is your responsiblity. If you want to work hard to keep him that means you need to get the help to help you to help yourself. When i was diagnosed i really really wanted to make progress, so i read a ton, asked lots of questions (still do) and more important was completely up front and honest with my therpast and Pdoc on what and how i was feeling.
Later when my wife commented to her doc how good i was doing he said it ws simply because i "wanted" to get better had done more than any meds had.
I start each day with a mental image of the man i want to be, good husband, friend, father, worker, etc. I try not to sweat the small stuff and concentrate instead on the big picture. Do i have bad days, yes, do i make mistakes, yes, but do i get up each morning , dust myself off, and try again. YES. This is a war with no end and no lasting victories. If i have had a good day than i celebrate it and know when i go to sleep i will wake up with a whole new days worth of challenges to keep me busy. I also know that if i fail, that tommrow is another day and that it is a whole new chance to be super Bill again.
You seem to be in a lot of pain right now, this group has some big shoulders to lean on so you go righ t ahead and lean on as long as you need. Before you know it you will be the one letting others lean on you.