YOu need the venting, and I'm glad you came here. You have every reason to be angry.

You can't FORCE a 16 year old to go to his father's house. I would think that your responsibility would be to remind him that he is his dad and wants to see him and have him in his life. That, no matter what, he is his dad. That, if he has problems with him, he should talk to him. The rest of the talking needs to be his dad doing it. Your son is angry, and he should be. Perhaps you could mention to your ex that he should get a counselor for him and his son to repair the relationship (which is what he should have done with you, Kat). Do you think he would do the right thing with his son at least?