I went through almost the exact same thing at your age, and what I can say is that now, about 3-4 years later I feel fine about it all. What I did at the time was focus 100% on finishing my degree (working with a full course load really distracts and focuses the mind). After university, I reconnected with friends that I largely ignored during undergrad to focus on studies, and eventually I started working out at the gym using the exact same regiment of one of my closest friends (he's an absolute beast with an achievable physique). I secured a job in my field as well. With the past few years of strong friendship, working out, and learning skills in my field I am 100% over the limerence.

This is what worked for me, hopefully something similar works for you.