this is getting out of control

so i wrote on this girls facebook wall about the dog...thinking she was my friend...she called my ex and told him what i did then she deleted me! then he texted me saying i was lucky to have her..and that he doesn't care if anyone goes after him he will make drama. and if I'm not lady enough to text him don't talk to anyone and if we could please be adults. and knock off the crap?? really! of course i didn't write back to him..but yet again my best friend worked with him tonight and he asked about me the whole time and now its getting in the way with her work and he won't live her alone with it. I feel bad but i can't make it stop. She doesn't tell him any info and he gets mad about it. I am so mad that this girl would do this, just the other day she was telling my friend that i deserve better and that my ex is gross and i don't deserve him at all...but may i remind you that this "girl" use to date my ex right before me..so i don't know if it was revenge..but i have done NOTHING ever wrong to her. i added her as my friend again because of the things she said about me..but now she did this. What is my ex trying to say? why is he trying to talk to my best friend every time they work together..he is the manager to them so she can't tell him to F off or anything. She doesn't even want to work there anymore because of him. I am trying to get her to switch locations and work with me..HELP ME!!! what do i do...i know still N/C but its getting to far