what do you do when you "love too hard"?

i get very attached to people. i can only speak of platonic relationships here, since ive never been in a romantic one but i cant even imagine how terribly i would do in a romantic relationship.

it feels like i cant be loved the way i love. i know the way i love is unhealthy and so i wouldnt want that for anyone else, especially not for someone i care for but it still feels terrible. no matter what i do i can never feel secure with another person because i feel like they will leave me even when they're acting like normal friends. i dont know what to do. i should be grateful for what i have, and i am, but its like its never enough