Being "nice"

Have you ever looked at a certain situation you were in, and thought to yourself, "This is not where I'm supposed to be"? I'm doing that. I love life, and I want to love everything about my life, but right now, some things are just NOT RIGHT. I look around and I think to myself, this isn't right. I'm not living where I want to live, I'm not doing some of the things I want to be doing. I'm just going with the flow, and I don't like the way I'm flowing, the direction, right now. I am trying to be as "nice" as I can be. But sometimes being "nice" gets old. Especially when it's not appreciated. I want to be appreciated if I'm going to go out of my way to be "nice". I'm sacraficing some of my happiness being "nice". I think I'm tired of being "nice". Is it wrong for me to be tired of being "nice"? I feel as though I'm being taken for granted, and that is what bothers me the most. I have no problem helping out and doing nice things, or even sacraficing for the sake of others, but I do have a problem with being unappreciated and feeling like I'm being taken for granted. I think that is what I'm tired of, because no matter what, if I have to do things for people and I'm able to do it, I will. But I just want a "thank you", or a "You don't know how much this means to me". I don't want to feel like I'm SUPPOSED to be doing things, when I defintely know that I don't have to.