Help me 😭

My boyfriend sent me this about an hour or so ago, we've been dating for 1 1/2 years, and i'm so confused and upset and i feel like complete shit. I love him more than anything in this world, and i'd do anything for him, what do you think i should do?! Reading this literally just ruined me. We're still together and i said its just a phase and we'll get through it, and i'm trying to forget about it. He's 19 btw.
"idk whats wrong with me really
I love you and i know i do and you're an pretty amazing girlfriend
but at the same time, part of me wants to be single and i dont get why
its got nothing to do with my feelings towards you i think its just got to do with being in a relationship, and im not saying i want ours to end
just all my teenage life, ive never been in this single stage where i can just do my own thing and whatever, ive always just from one girl to another, sure there is a gap time in between but not usually much with me πŸ˜•
and i dont understand how i feel completely and i hate myself because of it because i dont want to hurt you πŸ™ŒπŸ’•"