I was in the same boat when I was 26-27. I was passionate, better than most in programming and had a better job than most. However, I was not happy. There was this constant fear that somebody would overtake me or somebody is x-years younger than me but earns y times more or he is so young but achieved so much more than me blah blah blah. This eventually led to mild depression(or at least that's what I think it was). Then I started doing meditation. I don't want to preach but trust me it works. It made me focus on what's important and what's not. It made me realize that I am externalizing my happiness, that I am comparing myself to others when such comparison is not fair,that whoever I am comparing to might have problems of their own; nobody's life is perfect. But most importantly it made me realize that all my adult life I have been preparing to be happy without actually being happy. It's like this. If I do this project and publish my web app, I will be happy. Or if I conrtibute x-lines to some OSS and get my name on the contributers list, I would be happy. It was sort of like preparing your bed but never actually sleeping in it. So the TL;DR is start with a little bit of meditation.The Art Of Living Sudarshan Kriya and mindfullness would be my humble recommendations.