Why doesn't anything feel worth it anymore

I noticed a pattern in myself. I chase a goal, I achieve it, be elated about achieving that goal for a few hours (A few days at best, if it's some really really great achievement), and everything feels the same again I'm off thinking about the next thing. Once I've got it, my mind just goes "this wasn't such a big deal". I got a pretty nice rank in NEET UG and also cracked the internship at Microsoft. I have won hackathons. I have overcome my shyness about talking to strangers. I have a lot of things to be proud of. I came really close to killing myself but have managed to live on, and this is my greatest achievement by far. I just wish I could be happy.