Wow, I just read the opening post. There is a lot of weird stuff in that story.
I suppose it is possible that your wife did not sleep with this man, possible.
I believe that demons exist, so demons throwing you around the room sounds like the most rational explanation. I am not sure exactly how it works. I suppose it is possible that your wife or her male friend could have been involved in the occult. Maybe the prayers for death or some kind of curse tapped into something occultic. Or maybe they weren't 'summoned' by either of them, but you were both under demonic attack in different ways. If that happens again, command it to go in the name of Jesus. IF you don't feel you have the faith, call some other people to come pray for you in your house.
I have a friend who, when he was a child, saw a black figure like that at his bed. In the house he was staying in, doors would lock by themselves, he said. The light would come on when they drove over the hill and saw the house, and be out when they got there. They tested it when someone was at the house and it did not come on. They moved away.
Years later, in college, he'd gotten serious about his faith and was 'targeting' other people with a small group of friends to evangelize them, and a youth group near church was growing. There was also a witch cult the school administration was concerned about, and even spoke to him about it fo some reason. He said a dark figure showed up at his bed, summoned by a spell from the witches who were against him (not sure how he knew that when he told the story.) He said, the first time he saw the dark figure by his bed, he was scared of it. But this time, he wasn't scared of it, and he could sense that it was afraid of him.
Anyway, I'd ecnourage you to continue to grow in your faith, intercede for your wife, and take up spiritual leadership in yoru home. I want demons to be afraid of you and not vice versa.
If your wife says she doesn't ahve to do something ebcause she doesn't feel God leading her to do it or doesn't think something is wrong because she doesn't feel like it's wrong, you could remind her that she carried on that relationship for years and years. The Bible mentions people whose consciences were seared with a hot iron. You coudl mention that to her. If she says that it doesn't matter if she sins because God forgives her, read her that 'God is not mocked' passage, and the 'I never knew you passage' out of Matthew 7. If she doesn't go to counseling, tell her you are her husband and you want her to go to counseling. You could find something in the Bible (e.g. I Peter 3) to go along with that line of reasoning for her.
I would encourage you to pray with your wife and kids and read the Bible with them. I try to lead my kids in family devotions every night. My wife is usually involved with that. Sometimes I'll do it. Sometimes if I work late, she will. My wife and I also pray together. It's a good thing and it can be a blessing for your family. You can also spend time together praying for your marriage.
The Lord may use you to reach your wife and to restore your family.