Keep her always busy, as said do 8 and half passes, back up but never just circles. All elements that make her think, and switched fast should help.
Remember to give her rest when she has done things ok and not tried to pull you back home, when she stops and thinks on the trail after her panic attack.
Try to stop and rest facing away from home..
Ages ago someone told me the best way to stop a horse from rearing is to smack it with a stick when its reared up... then, I didnt know what to think, their logic was that once the horse feels bad up, it will stop. However, I would never try that method, ever.
I think you just need a lot more patience walking slowly further away from home. And also, do not decide to do all those exercises just when she tries to run home. Do them every now and then, so she doesnt have the time to think about running back. Make her do active walk, the walk with shoulder in, then do some backing, then do an 8, then do some side walk, etc etc. make her listen to you to hear what will be the next thing to do and she will have less tiime to go crazy and run home.