I relate a lot to this. I had a really hard time getting out of the college mindset and into the workplace mindset. Ultimately, for me, it meant finding a workplace that encouraged me to utilize my ADHD, rather than trying to control it; I can't say that that's what you need (since you may not have ADHD, obviously), but I do think finding a workplace that fits with the way your brain works is very helpful.

It also meant figuring out what I really want in life, and making sure I was working towards it! Nothing leads to burnout faster than feeling like you're going in the wrong direction.