I did not get in on the beginning of this thread, so I don't know the whole situation. However, I will share my custody battle story with you. My exhusband and I separated when our son was 5.5 months old. My ex probably has undiagnosed Aspergers. At the very least, OCD. He fell apart after the birth of our son. If you listenned to him, he would say that I fell apart.
He was so angry throughout the whole process. I did not want to strip my son out of my ex's life, but he wrongly believed that I did. He was positive that he was going to win every time we went to court. He was angry every time we went to court. He was bitter and hated me. He hated me more than he loved our child.
I won sole custody. I've been taken to court more times than the number of years that my son has been alive. I've never initiated any of the court dates. I've won everytime because my ex's bitterness and anger is obvious to everyone.
About the visits, you mentioned your baby regresses after visits with the mother. My son did too. Everytime he saw his father, he regressed. This was noted by speech therapists beginning at the age of 2. I had the regressions documented. I came to learn that the regressions were not products of something going wrong during the visits. It's just that transitions back and forth are extremely hard on my son (who does have aspergers). He likes one routine and it's not that the other house is "bad" ....it's just different. At age 9, he would prefer to not go to his dad's sometimes. It's not a lack of affection for his dad though.