[StevoRocket]

Your woman sounds exactly like my ex wife, mother of my only son, she always threatened to take my son away from me in arguments.
Eventually she ran off with her boss when my son was 11. After 2 years she got him to live with her. Then she started on the reducing contact ploy. Net effect is a son I see rarely after a period of 4 years when he refused to talk to me.
Now he's 21 I have told him why she left - why her brother wont talk to her and a few more hometruths. He's beginning to communicate more.
The real bonus of this situation was the wonderful woman I met through a dating web site - 5 years of bliss with a superb wife was a just reward for the pain my ex put me through.
You and your children have one life - one chance for some happiness - dont be a victim any longer.
Make your plan as mentioned above - get the advice and guidance you need and then get rid of her.