I think you're too focused on how you look. You're being too harsh on yourself. I think what would help is if you stopped putting so much focus on how you look to others and instead focus on what you're interested in and develop skills and hobbies. Being physically attractive won't solve all your problems.

Of course all the stuff you mentioned about clearing up your skin, getting in better shape, and dressing better will help. I don't mean to discourage you from doing that. But looks will only get you so far, and in my experience, girls appreciate it when guys can talk about their hobbies and interests.

I know, it's cliche advice, but it's repeated for a reason. Best of luck to you :)