I also experience the same anger, and I'm trying to decide whether it's an intermediary stage, an undesirable side-effect, or an healthy emotion that should accompany full apostasy. Possibly all three.
Anger, like every other emotion, is just energy - it's not good or bad, it's just a lot of pent up energy. It can be channelled for creative rather than destructive purposes.
It's seems much more familiar to deny our anger (which leads to Depression), or to hate our anger (which leads to Anxiety). But it's really necessary to embrace our anger. Feel it, acknowledge it, respect it. Then find ways to use the IMMENSE energy in your anger to create something that would resolve the issue that caused your anger. I'm not talking about "revenge" but of resolution. So, if you were beaten by your parents because you weren't religious enough, you can work in the world to help other kids who were abused. If you were molested as a child by a religious clergy, you can raise awareness about this issue, and help others.
Anger won't be repressed and it won't disappear. It just takes a some introspection, being honest with yourself and being self aware of your own choices. It takes taking responsibility for what you're going to DO with you anger.
It's not the easiest journey, to try to befriend and transcend your anger, but it's the most fulfilling one.