Welcome to SI, neverdidthink. None of us ever thought we'd be a part of this forum, but we are , on the upside it is a great place for support.
Have you checked out the articles in the Healing Library? Also scroll down in this forum a page or two and find all the threads with a target icon on the left-hand side, great reads for newbies. My personal favorite is Tactical Primer.
It will take an extremely long time, years, not months to get over the pain of infidelity. Your emotions will be all over the place, very normal, one day sad, one day angry, one day feeling ok. IC is a great idea, just be aware that not all counselors are trained in infidelity. Trust your gut with your counselor as well.
We've had a tough year and our communication really suffered
^^^Absolutely no justification for an affair, all marriages have ups and downs, there are other more constructive ways to deal with marital problems such as counseling. An A is the most destructive and easiest way to cop out of daily struggles.
Lean on us, lean on a TRUSTED family member or friend, lean on your IC.