how to stop caring so much about the men i liked?

i always give and give. i never receive the same love or care from the men who i give so much for. my high school relationship fucked me over. he took me for granted, compared me with other girls, and at last broke up with me as i couldn’t stop being desperate over him and obsess over making him happy somehow. even compromising most of the time and not caring about my own happiness first. my college life hasn’t been any different, been with 3 guys in a situationship, which affected me even more. what amazes me that it never bothers the guys, if the girl is there or not. they js need some fun. how do i get the same attitude. why do i always end up getting attached? when to stop caring about whether he got a better girl or not? when to just live life and not obsess over men i like at a certain time as they continue to enjoy their life nonetheless with side hustles. i wanna stop feeling this way. i always counsel myself but i come back to square one somehow. help.