Is it normal to not trust

OK, so i have some trust issues to almost everyone, my best friends, family, everyone. But it is kind of an another type, i dont really know, anyway I trust my friends when i tell them secrets and personal stuff, but I dont trust them when they say they love me. I love them to death but I just cant imagine that someone loves me back. Especially that much as i do to them. I feel that if i trust them when they say they love me, they're going to leave me behind and never come back. It have happened before with my old friends, maybe its therefor? Is this normal?