Peter......we all have regrets in life, and can search for things to feel bad about.
You do need to stop looking for things to punish yourself with, your analysing everything in search of negative things to beat yourself up with, when in reality you have nothing at all to beat yourself up with, it has to stop...
You cared for your lovely Bridget and I am sure she would have done the same for you, dementia took her from you, yes she is still there but it’s not the way you hoped and planned for, and that is so very sad, but we can’t change what life gives us...
Have you spoken to your Dr yet, as I honestly do think you need help, you have been in such a dark place now for too long, and it’s making you ill.
If the roles were reversed would you want Bridget feeling as you do, and being so tormented........I think the reply would be 100% NOT.
Peter, allowing yourself to have good days and the acceptance of your new normal ......does not mean you are forgetting or in any way a reflection on your deep feelings and love for Bridget, those feelings will never change, but for your own health you need to find acceptance.