Ready for divorce to be finalized and its only just begun

So tired of dealing with my soon to be ex husband. He is trying to get full custody of our kids and tries doing the parental alienation. His latest stunt was last night when he tried telling our 16yr old son that if he chooses to live with me that he won't be taking him camping or anything else he has planned for them this summer. My kid was incredulous that he would say that. Then last week he got upset with me and proceeded to scream at our oldest (the 16 yr old) that I was a stupid b#&*# over and over in a fit of rage. After he calmed down he then told our son that he probably shouldn't have said those things and told him not to tell anyone. Of course our son told me. The thing is, we have been separated almost three years so my ex knew divorce was inevitable. Its hard dealing with this and trying to stay strong.