I know exactly what you are going through. I'm going through it too. My brother passed away last Wednesday Feb.4 to brain cancer. It was caused from having melanoma 8 years ago. We had his funeral on Monday. He was only 48 and has left behind a fantastic, mature 25 yo son, both his parents, 2 sisters and a brother as well as 2 neices and 2 nephews.
I keep trying to remind myself that his suffering has ended but, for lack of better words, this really sucks.