Wanna Get Over My Ex Boyfriend

my relationship with this person already ended for more or less 4 years from now. Entertained someone after it, ig to fill the void of loneliness as well. I won't deny that this person do occupy my mind especially when i'm not busy but would absolutely not consider going back for any reason (though countless thoughts are making making sway but i do stand my ground) kinda push and pull thoughts.
Well, to start off, this person was my first love and has been a pillar of support for years. We were classmates from primary education to senior year. Strictly remained as best buds throughout this timeline not until one fateful online encounter during pandemic lol. I initiated contact through dms as a way of rekindling friendship in mind then we hit it off from that. We started playing games together, talked about interest, and got personal then suddenly this person dropped the bomb by confessing on a random afternoon. Then fast forward i did respond to the confession and became official, just classic young love story. Just as every relationship experience, there have been misunderstanding, negative emotions, and hardships, even went through multiple break up due to petty reasons.
Moving forward to college, I moved to another city for my education while he remained in my hometown. There was times where texts went dry and both of us got occupied with school. I initially thought I could handle ldr but the circumstance was unbearable and led me to decision to officially breakup. I would want to do what normally couples do in a relationship but unfortunately could not do it due to strict households on both side. Idk if it was even a mutual decision or I was just selfish for deciding on my own but a decision should be firm. Now, that person i believe is entertaining another and i genuinely wish nothing but the best for the them. I am entertaining someone new too and its not that steady much. I just feel guilty that i have these thoughts even with a partner by my side.