I don’t know if i ever cummed in my life

I masturbate and i always rub my clit until my vagina starts contracting and i have this feeling where i don’t want to do it anymore. i thought that was cumming. but my boyfriend told

me that u cum when there’s white fluid coming out the vagina and i’m supposed to know when. usually when i masturbate and i feel like “cummed” it’s usually clear. i’m just very wet. so my problem is. if i never made myself cum before how can i expect my boyfriend to. i want to experience it but i don’t get pleasure from fingering and when i stimulate my clit after a while i start breathing heavy and my vagina does that contracting thing and i’m not horny anymore.