Sorry you have had so much loss in your life.
I believe every funeral changes us in some way. Your perspective on the world is altered without that person in it. Maybe the best way to cope is to honor the person's great life by using it to inspire you to live better. Let even a tiny part of their legacy live on through you. I learned a lot about life from my grandmother and I will always use memories of the way she lived as a model of how I should try to live.