Why bother?

It seems like anytime I feel like I am moving forward, something comes along to throw me back. Something I though I had beat, something I was sure I'd overcome. I guess that's the way life works. But what I want to know is why I constantly put my faith in people and get my hopes up if I am only going to be let down?

Could someone come along and restore my faith in people? Please? Because I am about to lose it...forever.