Dont know what to do any more

I have been with a girl now for almost a year. I met her while I was married but we did not really start talking until after I was moved out and getting a divorce. I have 2 children by the ex wife. Now here is the problem after me and the new girl started dating the ex wife found out and was not happy at all because to her I left for another woman. Which is not true at all and no matter what I said the ex thought I was lying about that. So one day my ex ran into my new girlfriend and started talking to her, telling her that I had been txting her and telling her that I was torn between them that I still loved her and so fourth and so on. This really hurt my new girl very badly she also told her that she would do any thing she could do to get me back. I said if she told you that then there is nothing that she wouldnt do or say to ruin our relationship. So after a year of being with this new girl I still get constatnly drilled and questioned if I want to be with her and what all was said when I go pick up my children. It has got so bad that I have to talk only thru txt msgs and when I pick them up I wait in my car and she sits the stuff on the porch and when she goes in I get out. After all of this she still dont believe what I say. I have never been divorced before and at first I didnt see ne thing I was doing was wrong but now I try to do what the new girl wants me to with that situation such as talk only thry txts. The bad part is, is that now she questions why after almost a year I changed what I was doing and she thinks its because the ex wife dont want me any more and that she has moved on and thats why im no longer being nice to her. Also my new gf has 2 kids by 2 different people and she can talk to them whenever how ever she wants and she goes to there house and if i ever say any thing to her she gets pissed and try to turn it around on me. any help would be great thanx for reading