I am sorry you are struggling.

She has naked pictures on her Facebook? Is it even allowed? You said she sends them to a guy? Like in private messages? You wouldn’t be able to see those. If she publicly posting naked pictures, she might get in trouble at work. That’s weird how a grown woman wouldn’t think posting nudes online could be dangerous. Regardless, it’s probably best to stop snooping

It’s been only 8 months so it will get better. Stay busy. Focus on your kids and job and building new more satisfying future for yourself. It will get better