First off - you can't blame yourself for your W indiscretions. The encouraging stuff with flirting and texting is strange, but at the end of the day, she made those choices alone.
Secondly - counselors are important if you want to save the marriage. If you didn't like the first one, go to a different one. If you don't like them either, find a new one. Don't stop trying to find the right one.
Onto your DB Qs... I don't know much about the GAL in your situation... maybe try GAL with activities that she'd enjoy too. Get a bbsitter, take a salsa class. Whatever.
The OM - if you're NOT okay with her having an affair, I'd say push for NC. If she's serious about saving the marriage, she can't have a backup. They work together, right? Are you going to ask her to quit her job? If not. Ask for NC and transparency. If she must have contact with him for work purposes, have her share them with you so you know its over. phone too! She needs to be transparent with that too. If she's going out with friends, you need to know where and who with and how to reach her. It's inconvenient, but that is what happens when you break trust.
Phone therapy - no prep work needed. Make the call and set up the appointment.
Marriage is a PARTNERSHIP. I know you've both made mistakes but there is still hope if you BOTH are willing to put in the hard work to put the pieces back together.
When you are happy as an individual, you are in a better position to determine whether a partner enhances your happy life or weighs it down.
