Wow...as a single mother of 2 girls (6 and 8), I feel for you!! It looks like no one had any suggestions to give you, and I'm in no way qualified to give this type of advice. I hope you have found an attorney or social worker/someone who can help you with this battle since this posting has been 25 days ago.
I don't know if you've given all of the information (i.e. any mental illness on either side?). Also, I believe that children should be left out of adult problems. It is not fair for him to degrade you in front of the children - and as an absent parent, he has little room to talk about parenting skills. The girls are too young to understand this battle, and children tend to internalize the problems. Such a shame that they have to go through this, but unfortunately, I don't think that this is a good case for "mental abuse", as you stated...
Are there other factors that would make it challenging for you to get at least joint custody of the girls? How would this work with you both on opposite coasts? Are you willing to go back to GA to speak to a counselor or take parenting courses to show you're serious about this?
I can't imagine living w/out my girls and I hope you do whatever is necessary to get to spend time with them. They need their mother, and he needs to realize that. You stated that you are not an unfit mother, and if you can prove that, then the courts can't deny you the right to see them. I feel that it should be the childs choice (unless there is abuse/neglect) on whether or not they want to speak to their mother. He needs to wise up, or they'll end up resenting him for it! Some may disagree with this, but I have lived through it and having the father a part (however limited, due to mental illness), has made my girls more understanding of the situation.
Best of luck to you!