It sounds like the visitation agreement isn't the issue causing your dd's behavior - it's the fact that your ex is talking negatively about you. I would discuss this with the therapist and see if maybe the therapist could have a talk with your ex about how this is hurting your dd emotionally. Maybe he will listen more with it coming from a third party. If not though, there's not a lot you can do about it unless you have a clause in the CO saying the parents are not to talk bad about the other parent in front of the child.
So again, my advice would be to go to court to get a better CO.
Has he actually been diagnosed as bipolar? If not then I would request for a psych evaluation to be done on him. If it comes back that he is bipolar, I would ask the judge to put a stipulation in there that he has to be following the doctor's orders for medication in order to be able to take his visitation.
Have you tried talking with the stepmother? Maybe it would be easier if you dealt with her (if she is willing to do that). I know it's not ideal, but if the father is so unreasonable, it may be a good alternative.
So again, my advice would be to go to court to get a better CO.
Has he actually been diagnosed as bipolar? If not then I would request for a psych evaluation to be done on him. If it comes back that he is bipolar, I would ask the judge to put a stipulation in there that he has to be following the doctor's orders for medication in order to be able to take his visitation.
Have you tried talking with the stepmother? Maybe it would be easier if you dealt with her (if she is willing to do that). I know it's not ideal, but if the father is so unreasonable, it may be a good alternative.