Brain won't stop

I'm new here and hope to see if anyone has dealt with a similar situation. Loss of a 15 yr marriage two months ago. Somehow got into a depression. Lies, deceit and rudeness still affect me everyday as things aren't finalized. I've found myself in a depression that I know nothing about. I feel worthless, at fault and tremendously lonely. Many friends and family say it's not my fault (even he does) but I can't believe it. I feel like a total failure. Can't sleep, can't eat, can't focus and can't think so work is affected as well. It's been two months and doesn't seem better. Highly struggling. Sleeping a lot and isolating as much as possible. Anyone experience anything similar?