I'm so sorry SnowyRiver.

I hope and pray that you can find peace, comfort and joy from the Lord. Lean on him and his Word. It will bring you healing.
It's difficult but you can overcome this! Allow some time to cry just to yourself and eventually realize that you are better off without her. What do you want a cheating wife for anyway? Thank the Lord that you are freed from that. It's best that you found out now than before you got an STD or something.
When we go through difficult things, I have noticed that the Lord puts something new in our lives. Maybe this is a chance for you to lean on him more? Maybe you can focus more attention on your children and grandchild? Maybe you can start serving more at church? I recommend you do something like this. Get involved and make friends at church. Talk to your Pastor or male friends and just fellowship.
Do things for yourself. Take a walk, eat healthy, maybe take some college classes for fun? Just get out there and meet people. Don't sit at home for too long moping. It's not going to do you good. Yes, you can grieve for a few weeks but after that, you need to move forward.
Things I recommend you don't do
-don't speak ill of her in front of your kids (she will always be their mother)
-don't date someone else right away (you need time to heal)
-don't blame the Lord (we all have a choice and she chose to do this)
-don't hate her (she is a child of God just as we all are, and she obviously needs prayer)
-don't call her or take her back unless she has proven to you that she is ready to change
Again, please lean on Jesus and forgive her. The forgiveness is for yourself. You need it to heal. God bless you and may you find the Lord's peace
