Idk what to do with my life..

the guy i want to marry and have kids with doesn’t love me anymore. we were dating for 3 years and he said he’s not feeling the same anymore. idk what i did to him. guys always seem to leave me and not wanna be with me . Im tired of trying to find the one cuz once i give them my all, they throw it all away. i feel sad and confused .i don’t know if i can even be with anyone anymore after this relationship i’m alone and depressed . I have no one