Military divorce with kid on the way and another is 32 weeks in the womb.

Hello so currently in the military as a e-4 in virginia on sea duty orders. Found out my wife has been cheating for over a year now over the phone with some guy out of state. We got a 2 yo and another coming soon. She has a mental issue where its hard for her to do things on her own IE: count ,can't drive ect... I know driving isn't a mental issue. I want a device but I don't know what to do, I want to keep my kids safe but dont want to be around her. Not yet sure what I need to do or can do and how things will play out.