I had crush on my only best friend but ...

I try to keep this long story short!!

it was a year ago that we randomly got familar online. i was talking to him everyday about everything. we had many same ideas, point of views and i was really enjoying talking to him. it was like I finally found someone who underestand me and is cool! as an introvert I barely can find friends, specially a close friend.

He wasnt like me I knew this. He had many friends either irl or online unlike me. we were too close. we were talking about everything i have never been that much open to a boy before. it didnt take me much till I realized I like him. but to him I am just a friend. yesterday when I saw a girls pic on his profile- someone whom he was describing as a girl who he would like someday!- congrating her birthday I litrally felt a heavy emptiness on my chest like sth i have never experienced before. im a sensetive introvert so i didnt tell him anything about it i just asked him to message me less and that i do the same, then i removed him from my IG at least to not see him every where, he didnt know why im acting like that and that made me crazy, but i dont want to tell him anything i dont want to humiliate myself this was.

i felt like it was a toxic friendship for me. i fell for him easily. i didnt want to break myself more but everytime seeing our chats i cant stop my tears. and the fact that he know nothing about this is breaking me more. this is weird i dont like to feel this. i dont want to be a pathetic person loving someone who would probably not care about my feelings. . i wasnt suppose to be sensetive on him because we were just friends but idk why this happened and why i made myself fragile.

i litrally dont know what should I do

should I tell him why I prefer to not be friends anymore? or will that break me more?