Is there an end to always?

It has been another one of those days/weeks/months where so much of my life and schedule is dictated by events and people I have no control or influence over. I can put my heart and soul into doing what I truly to be the best thing, working devotedly to doing a good job, and then this all-powerful hand that has never once met me or bothered to ask me a question, can come and squash my efforts. It has nothing to do with me. Nothing to do with my efforts, and just the whims and ideas of an outside party. The apologies always come down with "It has nothing to do with you... It isn't that we don't think you can handle it..." And while I know that those comments are somehow supposed to make it all better, it doesn't. In fact, it is more insulting. My efforts are a part of me. I put a part of myself into everything that I do. And then someone comes around and says that it was insignificant. How can I help it if that makes me feel insignificant as a result? Is it even fair to ask someone to do something so insignificant? Is it fair to ask someone to devote their efforts and energy to a project that you consider to be useless and unnecessary?

I'm not angry. I'm just tired. I passed angry ages ago. Now it is just par for the course. Kill myself for something that will go completely unnoticed, and then be forced to accept that it had nothing to do with me. How can I not feel jaded and tired? It always makes me think "Payback's a bitch." There is no good karma. Doing good does not come back to help you, does it? After all the patience you have expended doing the right thing, being there for others, and hell, just faking enthusiasm and support, what does it get you? In my opinion, walked on. It makes you the person everyone knows will always just be there. Always forgiving. Always doing a good job, even if no one will appreciate it. And then everyone will always continue to take advantage of that. Why not? You've always forgiven everyone else. You've never complained about the abuse. You've always just been the one who does the good job, even if it wasn't warranted.

Is it possible to ever really trust again when you feel this taken advantage of? Do you intentionally choose to be jaded just to protect yourself? Is there ever an end to always?