I just don't understand

I have been trying very hard to keep a positive outlook on life. To keep my spirits up and practice lovingkindness toward others. I have been trying to help others when they are down on their luck and show true care and compassion. I also work hard to learn more of the Bible and of God so I have a better understanding but life just seems to be getting harder. My son had a huge fever yesterday, I am very grateful that is broke and he is fine, but it still takes a lot out of ya. I also just learned that the man I was in love with and just can't seem to get over is already living with his new girlfriend, something that he would not do with me even though we had been dating for over a year and he has only been with her for about 4 months. I am stuck, I am in a low dark place and no matter how much I try to be a better person that does not care about those kinds of things I get slapped in the face with them. I am not trying to bitch, I am just trying to understand where I am going wrong. I want to be happy, I am doing things that are supposed to make life easier and happy, yet I just seem to get barried deeper and deeper in a darker hole that will not let me breath. I am sufficating in the place. I need to breath, I need light, I need to be happy, I need help... I am dying.