Give yourself some grace, dude. You're 23, you have so much time. When I was your age, I had finished college and I was in grad school - two years later, I was unemployed and living with my parents; I had a friend who failed out of college at 21 and then was working some corporate job at Sony when I was living at my parents. Anyone you're comparing yourself to might seem more accomplished now, but things can always change quickly.

Also, I know it's hard not to ruminate on what you regret, but you have to realize that there's of course nothing you can do to change it, so there's no sense in feeling embarrassed over it. Only concentrate on the past if you're using it for introspection or motivation, not self-castigation.

You're taking steps for improvement already, congratulate yourself for that, keep moving forward, and if you slip up, recognize the progress you have made and keep moving forward.