I know this does not make you feel better, but anger is a natural stage of grieving. As you go through the stages, there is denial, anger, bargaining depression and acceptance.
Throughout these stages, you must allow yourself to feel these emotions for they are healthy and they show recovery. If it seems that a certain emotion is dwelling and not progressing, then seek some counsel to help you through it.
I felt it when I lost my sister of 32 years, then all four of my grandparents and a marital breakdown. Whaever you feel let it out.