How to let it go?

Hello. I'am 21 years old. I can't point a finger on why i feel this way, but today was pretty bad for me. I felt weark physically and empty and cryed. I grieve that my relashionship with my family cannot be full, loving, meaningfull. I can't imagine loving these people again. I can't imagine they will ever accept me. But i cannot help but clinge to that. To those fantasies. I can't imagine what in this world can replace a loving supportive family. When i think about this i don't understand why i was born in the first place. I feel like i should stop mourning it, cause... i don't know. Everytime i remember it. Them. Everything in the past... i feel pain and it's hollow inside me. And i don't know what to do with it.