Feeling down

I don't know what else to do. I've just been feeling down lately and I can't tell anyone about it. I don't know, it just feels like no one ever stays with me.  Everyone who I've been with, if I don't give them "the one thing" they're looking for, they leave. Even if we see each other, they act as if I don't exist. I just want someone to stay, if that makes any sense. And I can't tell anyone about this because of it gets back to my parents, they will absolutely not get it. In fact it'll turn into a big mess. I feel like I can't trust anyone and I don't want to live like that.