I had similar to this, the Ex cheated on me then stopped me seeing my boy, and threw accusation after accusation, i went to court for years, first having supervised contact, but now i see him every fortnight.

The only trouble is, even if the court orders the mother to make contact with son / father if she doesn't nothing happens as they cant leave the child without a mother (if they jail her) they cant fine her because the child then goes without.

Hopefully having that court order will frighten your Ex into letting you have regular contact.

Good luck mate