Wow, that’s a heavy question, but thank you for it. I try and answer everything people ask, publicly or privately as you wish.
So firstly the obligatory public service announcement about depression and rest. Please make sure you’re talking to someone who can give you professional advice as medication and just talking to someone honestly can make a world of difference.
With the state of mind you describe I want to make sure you focus on the positive sides of edging. Which is about it being fun and sexy and helping to turn your overactive brain off and reduce you down to a more basic, horny little slut who just forgets about the worries of the world for a while. So the big thing at first is to see it as a game where CUMMING IS NOT A FAILURE. You have to learn how to edge and enjoy that before you can really engage with the more complex aspects of denial, like using it as a punishment.
So to begin with, instead of just trying edging, play with yourself and see how many times you can get yourself really close to orgasm, without going over the edge, but then push yourself, deliberately, further and further towards the end so you DO go over. I think that will help you not go numb, knowing that an orgasm lies at the end of the exercise.
Try different ways of stimulating yourself, a mix of fingers on and in you, any kind of vibrations on your clit and a dildo or (safe) substitute to fuck yourself. Basically have fun exploring how many different ways you can give yourself pleasure (don’t forget breasts too) and then finally reward your efforts with an orgasm.
Once you’ve got comfortable doing that, then you can try skipping the orgasm at the end and make the denial a longer term, more complex, affair.
I hope that’s useful!