This is a familiar voice (it is in my head also)...
Ways I can (sometimes, enough of the time to go on) chase this away for a bit:
Strenuous exercise (not in a gym(unless it's a group I can drop in and out of like aerobics when I lived near, and could afford it...), but hiking a mountain, or riding a bike, ---problem is the pull to the couch of depression, has to be (initially) forced but works.(I am always good -mostly- when I go camping...when I lived off the grid, alternately, I would occasionally get a room at a nice hotel...just for a night.
Telling myself that really, no one is that interested in me vs the rest of the world/people/themselves to be bothered judging me. Who am I to think they bother?
Painting (no I am no artist)....just the colors, the brushes, (again, takes an effort because all the other things I "should do first" come to mind)---ambient music and paints really help for the time I use them...
I am knitting a sweater for my grandson....unless I am too anxious and mistake-poised, this helps (a project that needs to be done by a certain time can help, for me it is the sweater by Christmas)
Treat yourself nice even if you"don't deserve" it----whatever seems nice. Me, I have been meaning to buy candles----because I like candle light (& oil lamps), perhaps a light incense, warm shower with great soap..cup of hot chocolate with cream & peppermint, or iced tea with lots of lemon & peppermint
I generally feel good when I am either out in the woods, or walking a city (love Manhattan for this...been a while) neighborhood with my camera.
I have to yell back "shut up" a lot....
What I find upsetting, are the times I feel Really good, and think I have really moved on only to have the curtain drop unexpectedly again, at the worst possible moment (sometimes external events, more often internal)
It is difficult to get over the sense of being betrayed or "fooled" into thinking happy/positive/hopeful thoughts, having those good feelings only to have them snatched away----hard to know this is how it is so the good things have to be relished...
sorry for the ramble...I am ....well, guess I better change my mood.