I don't think you need to say anything to your children yet. They need you. Spend time with them more and more. Look up on the internet for games you can play with them. Do something different. Cook with them. Sing with them.
Do you want to file divorce under adultery? Or do you want to save your marriage?
Make changes and focus on yourself.
Me: 43, W: 43 M: 16, T: 18 D - 7, D - 7 ILUB: 26 August 2014 Still living together