I know you don't want to hear this but, forgiveness is necessary for you to heal and move on. Anger is overated anyway. If you forgive your brother, it will ease so much pain in your heart. If you donot forgive, G cannot forgive you. Your wife participated willingly and who knows, may have iniciated(Spellcheck?) it, so why anger at him? Growing as a person includes forgiveness along with pain.:ghug:
I find the act of forgiving those who have wronged me to be very healing. But grieving's a process, and when the wound runs deep, it can be a very long, and drawn out. Takes considerable time to work through the stages, and sort through the various emotions we need to experience, in order to heal. The stages are nonlinear, and can flip flop and recycle, but at the end of this journey, we finally reach the conclusion, gaining acceptance, coming to terms with our loss. Performing the final act of forgiveness, can then bring peace and closure, but that comes a long way down the road.
Divorce is painful because it represents loss of all that was, and could have been. When compounded by betrayal of infidelity, the pain is excruciatingly profound. Getting past the initial devastation alone normally takes about a year, and depending on a number of factors, full recovery averages between 2-5 years. It's only been a couple of months.
Experiencing anger and resentment is a natural response to divorce that is pretty much universal. It can be very constructive in helping to detach emotionally from your former spouse, and enables us to face situations that would otherwise be intolerable. Anger fuels us with the energy and motives us to take action to bring an end to our pain. It also staves off depression, which is paralyzingly. Anger becomes destructive if you allow yourself to remain stuck in it too long, or if expressed in destructive ways.
Jesus himself not only expressed anger on several occasions, but upon discovering his father's temper had been turned into a "den of thieves" he became violent, overturning tables and fashioning a whip to drive them out. I somehow doubt that God holds us to higher standards.
For everything, there is a season. There are times where anger is the proper response, and I would say that for your own brother to have an affair with your wife, resulting in your divorce, fits the criteria.
There is a season for forgiveness as well, and in time, hopefully that day will come. But today is probably not that day.