I've struggled with self-loathing for so, so long... In the physical arena, I finally was able to let go of it completely about five years ago. This was entirely due to 1) meditation (self-acceptance) and 2) recognising that I can't do a bloody thing about my general look, but I can do something each day to take care of the body I've got.
Self-acceptance meditation lead me to start exercising, just a little tiny tiny bit every day -- honestly, like two minutes to start with. Core muscle exercises like planking, super-easy yoga that doesn't require contortionist abilities (will never get there myself

), stretches, walking up and down one flight of stairs at work. I mean, real fitness people would have laughed at me calling it exercise.
Then I expanded to three, then five, minutes. On a whim, I grabbed an old shirt and a pair of shorts as exercise clothes. I'd change into those, do something, change back out into day clothes. No shower required. Weirdly enough, the clothing change made it stick. It was oddly satisfying to go through that ritual of the clothing change. That led to changing my eating habits because I wanted to, not because someone told me to or because I was desperate, but because I wanted to feel better during that "exercise ritual" time.
As predicted, it hasn't changed how I look very much. But it's made a world of difference in the way I accept my body. Will I ever reach Arnold Schwarzeneger status? Not a chance. But that's not a goal. Just losing that feeling of hating how I look was.
End of story!