Guilt is very hard to deal with especially when it is linked to depression. I find that when I feel guilty I try to take a step back and analyse the situation - almost like an onlooker, what did I do, could I have done better, if so what and was it reasonable? Most of the time I come the realisation that I did what I considered best at the time and I cant change any of it - feeling guilty is just impacting on my present relationships and is literally damaging me . If my actions negatively impacted on others - I apologised to them - invariably it seemed they didnt even think I had done anything wrong - or, as in a few cases, we hugged and I was forgiven. Don't be afraid to admit your guilt. But please dont hold onto it for too long - it will only eat you up. I understand your wife cant speak - but can her eyes talk? Look into them tell her what you feel and then just hold her. She needs you now just as much as you need her. Sending you big hugs

Guilt is an awful thing to live with. I have so much guilt about my mother’s decline and eventual passing. There are days I replay everything in my mind and kick myself. But I know that is unhealthy.
A phrase I learned in my spiritual journey is “you do the best you can with what you had at the time”. We all have things we wished we did differently, but hinedsight is 20/20. All you can do is move forward.
The advice from RozanneRoy was very inspiring. I think it can help you moveing forward.

Be kind to yourself. What would you say to a friend who approached you with the same feelings that you have? I’m guessing you would be kind to him. Think now you would treat him. If you can be kind and caring to him, why can you not be the same to yourself? This idea was put to me by a therapist and gradually it has helped me.
I have suffered with terrible feelings of guilt over letting my mother go into a home. Whatever people say to me I always come back to the same thought….could I have done more? In my heart, secretly, I still believe I could have. But now I accept it and am more forgiving of myself.. I remind myself that at the time I felt I couldn’t go on any longer.
RozanneRoy has given you great advice…I hope you can find some peace, o body needs to suffer forever..allow yourself forgiveness.

Forgive yourself, ask God to forgive you. Jesus died for our sins. He probably already has, now you need to forgive yourself.

Major depression is an illness, just as a stroke, diabetes and so on. You have nothing to feel quilty about. If you had the flu, would you feel quilty that you had to take time to take care of yourself. It is a brain illness. It is a difficult illness to deal with. People who haven't experienced it, don't understand what happens to you ( the sadness, the lack of motivation, eating too much or not enough, neglecting your hygiene, how you isolate yourself and so on. I would study as much as you can about this illness. The more you understand the illness, the more you will understand how to deal with it. Sorry for the misspelled words. Education is a very important part of understanding this illness.