A self-aware nice guy!

Don’t be so hard on yourself. The negative self talk really doesn’t help. You know this already, but probably don’t know how to stop it.

Some framing that might help: you are human. You’re allowed to make mistakes. Just because you’re not perfect doesn’t mean you are worthless. Your flaws are much smaller than you make them out to be, and flaws themselves are just areas you can improve in if you put your mind to it. You have a good mind, so use it to build yourself up and be the best version of yourself. No one else is watching you, really, apart from the guy looking back at you in the mirror.

Sincerely, a recovered NiceGuy™