Are You Incapable Of Happiness?

I find myself asking myself this all the time. I believe I'm a fairly happy person. Most of the time I'm in a good mood, but then something happens I just feel as if theres evil forces out to ruin every happy feeling I have. I know, it sounds crazy. But thats just the way it feels for me. Its not that I hate my life. I actually love my life. Being able to live with the person I love & have a beautiful baby is great. With marriage & any relationship for that matter, there will be arguments. I feel like I am very argumentative though. Lately because I've been down & feeling as if my happiness is being taken from me, it's been a little more than usual. I take the blame for that I do. But do you ever feel as if some people just say negative things to you when you're happy just to upset you? Maybe I'm thinking too much. I am bipolar, so it could just be me being overly emotional as usual. We'll see though. I'm really hoping that I can be a lot happier in the future. For my sake. And my daughters.