I guess what i have had for years is depression. now i can almost feel myself slipping into a black hole. is that what it is?

Can: Depression feels like falling into a hole as well a variety of other, loss of energy, motivation, drive, change in sleep and apetite, poor concentration. It is very treatable so don't hesitate to get professional help. I discuss some treatment experiences in my book, psychiatry in techno colors, on amazon.Com.

Could very well be..: "slipping into a black hole"... Sounds like a pretty intense and deep depression... I strongly urge you to connect with a psychiatrist and a psychotherapist. Wishing you well!