emotionally detaching from someone you never dated

ok so.. im gonna try and keep this short and sweet
for context - i started college this year and met this guy, added each other's socials, talked abit in person and on ig, nothing really serious or anything.
before he would apologise for not replying and being active much bc of exams, and once exam season was over he would respond almost instantly.
we haven't spoken for a few weeks now, i barely see him around and when i do its just eye contact and no conversation, nothing online either. but he reacts to my stories almost every time i post them and last time he replied to one, but left me on read when i responded back. its kinda draining having to keep up with someone who keeps changing their mind, so i have been trying to detach as i am someone who becomes attached easily.
ik hes not interested, idrk what changed but thats fine. i just dont understand why every time i try cutting him off it backfires and its almost like hes trying to circle back. how can i stop this from happening and just let go?
advice is appreciated dudes

It sounds like he's not immediately interested in you but he wants to retain you as an option for later. I think you can do better, i.e. someone for whom you are their first choice.
I'd recommend just going no contact with him and immersing yourself in other things - your studies, clubs and societies, hobbies, socialising with other people, etc. Is there a way of configuring your social media so you don't even see if he looks at or reacts to your stuff?