Pride hurts

In everyone's life, there are always a few events or moments that we just cannot forget. These moments may be unforgettable due to pain, happiness, or pivotal events.
Although happy moments will always bring us smiles, it is the pain and sadness that seem to linger longer in our memory. We seem to always neglect or understimate our happy phases, and just say "I was happy", and move on. When it comes to the sad moments, we always seem to wonder and create several possibilities as to why things ended up the way they did, and what did we do wrong. And keep blaming ourselves for everything.
I seem, every now and then, to remember that boy who made me feel worthless. That moment that I regret so much when I said things I really didn't mean to my brother, that moment when I was mean to my mom and dad. Those moments. They hurt a lot - especially the ones that I know I was the cause of pain. And they hurt even more because I am far away. Being away doesn't get easier with time, as I thought it would. It just gets worse. It gets worse because I don't know when (or if ever) I am going to be with them again. It hurts. What can I do?
I guess the answer to that is to just learn with my mistakes. But it seems like I can't do that very well. That night when my dad got home from a long trip and he brought me a new pair of PJs. I stood on top of the stairs looking down on my dad, REJECTING HIS GIFT. I can't even think about this moment without my eyes watering. I don't even know if my dad even remembers this, but I do. I was probably six or seven years old, but I remember that day like it was yesterday. I remember how those PJs looked like. Eventually, after much begging from my father, I accepted his gift, with an ungrateful, angry expression. Eventually, I started wearing those PJs every day - until there was big holes on them and I couldn't possibly wear it anymore. Why was I so angry? Because he hadn't been home? Well, he was now. Why didn't I enjoy his presence instead of holding grudges? I don't know. But I seem to STILL do the fucking same thing today. When somebody hurts me, even if they have turned around and done something nice to me, I JUST SEEM TO HOLD TO ANYTHING THAT HURTS. Why do I do that? I guess this is just a rant, as I want to change whatever force within me obliges me to hold on to those moments. Pride? Or just plain stupid?
God, please help me let go of those things - they don't do any good. I hope I can become a better person, and I need You to guide me and help me discern what to do so I can let go of my pride.