Should I tell him

i’ve been best friends with this guy for two years and we’ve liked eachother on and off but never dated. When i saw he was starting to get close with another girl i distanced myself bc it hurt so much i couldn’t take it. It’s been a month without him and i cry every day and i miss him so much i just can’t seem to move on. I feel like the only thing that will help me move on is closure because he doesn’t even know why i distanced mtself and all of that. I want to explain everything i even wrote out a paragraph but i made sure to say i don’t want it to change his realtionship with her i just needed to get it off my chest. Should i send it? I don’t wanna be that girl but i don’t know how else i’m going to move on.