Why is it so Hard to be a Good Person?

I've resolved myself this year to get rid of this black hole in my heart. This pit of anger and frustration and hatred has been eating me alive for the past three years and I've realized that everything that has happened, I could have changed. I realized that I have completely control over my life and up till this point, I feel like I've been a lost lamb doing only what I was guided to do. But this lead me to hate the world and people and to blame things on others when it really was my fault. If I had tried a bit harder, if I had been more prepared... this realization has opened a door of so many questions and uncertainties, I feel as if the solid ground under my feet and the solid ground of my perspective and understanding is gone. I've tried to be more patient and understanding, thinking internally of all the reasons why something might have happened and why a certain person may have acted a certain way but it's just so hard to keep myself from reverting back to blame and anger and anxiety. I want to change but it's just so hard to fight against the habits and the inclinations that I have. Can people truly change?

My perspective is so clouded and one-dimensional. I fail to understand people and I'm dissapointed to say that up till this point, I didn't even make an attempt to try and even empathize. I'm worried though. I feel like if I miss this opportunity to become a better person that I can never change and that I'll be this pessimistic, jaded fool for the rest of my life. I want to see the world and experience life is different ways.

I've been doing a lot of thinking as well. What is it that I live for? Why do people live day to day when there's this endless cycle of suffering? Is there such thing as an omnipotent, benevolent, and omniscient God? Why do I do the things that I do? Why can man think and feel? Nothing I thought I truly understood matters in the face of these questions. There are not real answers and its all up to the individual to decide what they believe. But what do I believe?