40 pffft! You're just a bit of a kid. Hardly out of short trousers.
I retired from playing Sunday League soccer when I was 40 and that was many years ago.
As for being depressed? Best cure for that is six laceholes from a size 12 steelie up the jacksy. Sort yourself out and stop feeling so sorry for yourself. You've got a lot more going for you than millions, if not billions, of others in the world.