Puppy...it is only because I have seen so much divorce in my own life, plus now seen so many divorces at my work...that I know that it will be much harder than you think it will. It always is. Your emotions will run deeper than you think they will. Yes, even worse (or on par with) the emotions during her affair and afterwards. I know it doesn't make sense intellectually, which is why so many people ignore this advice and try to go through it with no counseling or support group. Because intellectually, it seems like "well this is just the end of the process, we've already gone through the hard parts". But that just isn't true. The hardest parts are yet to come, and no it has nothing to do with your particular sitch.
The attorney I work for has been doing this for over 20 years, and she actually specializes in mediation and collaboraton, she will not do litigation because of the painful situations involved. And she also specializes in uncontested, amicable divorces. And yet STILL, she tells every client who comes in her office door to get a divorce coach or an IC who specializes in divorce. Even if two people are just happy to be done with each other, there are emotions that come into play which they never expected.