I feel for you. I don't have any answers. The first year was hell for me. My ex and I have 50/50 custody. I never should have agreed to it. But I did not realize at the time that my ex had a 'real' problem. It appears that he is a narcissist. I figured this out with therapy and looking back at many examples of his behavior over our 14yr marriage.

Using the "NO CONTACT" technique keeps my ex at bay for the most part. I only talk to him when absolutely necessary. Other wise use email, txt messaging.

As far as my son-he soon realized what his father was doing to me and to him. He is coping with it and has been in therapy for quite a while. It helps him understand that how his father behaves is not his fault.