Dealing with Anger

I’m curious about what advice you could share with me about dealing with anger.
I recently turned 30, I am single, no babies and live in Arizona. I live a little life, but I am overcome with huge anger. It started after a devastating break up about 5 years ago. For an entire year after that break up I COMPLETELY shut down. I was not the same person anymore. I became very depressed, suicidal and isolated. Although I somehow got thru that period and now have a new love, a wonderful love in my life, why am I still so angry??? There are many triggers that set me off; from someone cutting me off while driving to something non-significant like not finding a pen when I need one. I punch the wall, throw a tantrum. Scream. I never was this type of person. Never. Not even as a child. Now as I am getting a little older, I DO NOT want to spend the rest of my days this way. So many others around the world are suffering from starvation, disease, abuse. So many are in far worse circumstances than myself. So what’s my problem? Why is it so hard for me to deal with my anger? I get plenty of sleep, I exercise, I eat right. But unfortunately with no health insurance I cannot speak with a mental health professional.