My boyfriend saids this relationship wouldn’t last long

WELL... by the title of this topic gives this discussion away.

He just said this.. And i don’t know how to feel.. I’m a late bloomer, I recently had a birthday and turned 21.. and he’s my first official boyfriend... (i’ve never had a valentines in my whole entire life and etc..) but we had an argument on my birthday and more he’s saying this...

I don’t want to leave him but if he doesn’t want to fight for this relationship i might as well leave.

Any encouraging words/ advice? I’m kinda sensitive to harsh and rude comments.