It seems to me that you are very depressed. And that's understandable given your situation. I know it feels hopeless. Its not but that doesn't change how you feel. Are you able to go to a doctor and see about getting put on an anti depressant? There is no shame in that. Its fine if you don't want to file for D. You have to do what you feel is best for you. If he is just a WAS, I don't think that filing would do you any good. Time and patience is what is needed here. Time for him to think about his needs and wants and to work on himself. And most importantly, time for you to work on yourself. Its a horrible feeling but you do have a tremendous opportunity. You have the chance to reflect on your life and what you can do to make it better. Not for him or to bring him back but to make yourself a better person. To learn to be confident in yourself; to love yourself. Doing these things are what will increase the chances of you being able to save your M.
Me: 48 y/o W: 47 y/o Together: > 20 yrs BD: Dec '15, then S 2nd BD: Mar '16, then I filed for D April '16: started piecing