You are pretty much at the point where for many people anger is at its worst. From reading up here on SI it seems that many people have intense anger at about 6 months - I think the shock and disbelief have had time to wear off and that's when the anger really lets rip.
Between 4 months and 9 months I was a walking ball of rage. It was ugly!
Time definitely helps. Keep reading up and educating yourself about infidelity and the trauma associated with it, keep talking to your spouse... and exercise - exercise definitely helps me cope with the pain and anger. I was reading a book a couple of weeks ago and it explained that anger is energy, that pent-up energy needs to go "somewhere" - you can choose to expend that energy by yelling and throwing your crockery around the room or you can expend it by doing some form of exercise or chopping down a tree or something (the book explained it WAY better 
) I reckon it is to the benefit of my relationship if I expend the energy doing exercise 
(unfortunately I don't always take my own advice, we have had to buy a LOT of new coffee mugs in the last few months....)
