It seems you are preoccupied with the notion of age, thinking that it should somehow relate to ability. It doesn't. While we all may follow a similar curriculum while in school when outside of academia age has little to do with where you're at.

Perhaps you recognise that peer-pressure & comparison is a huge motivator for you (it's probably what got you through your CS degree) you are trying to use that stick to force you to work more. However it's having an adverse effect on you. You cease to enjoy anything.

Try and make something small, just for you, just for fun. Focus on being happy instead of perceived success. What if you just let yourself enjoy your TV show or browsing HN? You may feel freer to enjoy your work.

You are not behind or in front, you are exactly where you are at right now.

You can't run a race if you're busy looking over your shoulder.

Your mention of feeling jealous reminds me of a quote from Mary Schmich when talking about advice she would give to the younger generation.

"Don’t waste your time on jealousy. Sometimes you’re ahead, sometimes you’re behind. The race is long and, in the end, it’s only with yourself."