Negativity

I dont understand people. Why would anybody want to live their life feeling sorry for themselves and getting others to feel sorry for them as well? I cant help think about how sad of a life that would be. Yes, everybody has their problems, and yes, everybody goes through rough times, but why dwell on them? Something positive can come out of any situation, you just have to be willing to look for it. I guess if you are constantly dwelling on the negative aspects of your life, then finding the positive is impossible. For what it is worth, I have been there. I went through a period of several years of being negative. Let me tell you, it takes a lot more energy to be negative all the time. Soon, the negativity starts to zap the energy out of those around you as well. Once that starts to happen, nobody wants to be around you. Thats what finally helped me move out of that phase of my life. I realized that I really had nobody other than my husband. I cant say that we had the greatest of relationships at the time. Slowly though, it did start to get better, one day at a time. So now, I look at the situation I am dealing with now...I am was not the negative person, but rather the one always trying to bring the positive into this persons life. I got to the point where I no longer had the energy to deal with it, and now I dont. I just sit here and try hard to not even acknowledge that the person is in the room. Now, at a point in their life, when they probably need a friend more than anything, I am not there for them. Why? Is it just too hard? Or have I come to the conclusion that I cant change anybody else? Maybe, I am just trying to live for myself now and trying to find the positives in my life by limiting what negativity I can. Does this make me a bad person? Am I selfish for wanting to be happy?