Need to get off my chest

I know I'm gonna get major hate for this but I need to say it somewhere and also maybe someone will understand and give me some advice/encouragement.

I have been part of my stepsons life for almost 4 years now. I met him when he was 2. He used to love coming to mine and my husband's house and adore us and our daughter (his sister). His mother (my husband's ex) currently has sole custody and the past 5 years my husband has been fighting trying to change it to joint.

Before someone throws shade my husband was 22 when he had his son with his ex. They realized once he was born they weren't gonna work and seperated. They were seperated and talking to others but friends and still sleeping together and he would go to her house to see their son and vise versa. She was going to school to be an attorney so he STUPIDLY signed the paperwork she drafted up blindly. They didn't do lawyers or court just themselves and then notarized and sent it in. He has regretted that everyday.

Husband and I FINALLY saved enough $ for our attorney to do the full switch. Changing custody to joint 50:50 exact split for access time and decision making. We have been in and out of court for 3 years doing trivial things but finally made the big move.

Ever since we filed the paperwork she has been emotionally and psychologically abusing and tormenting my step son. It's to the point where I don't even look forward to our access time with him. She tells him that he's not safe at our house, and that his sister isn't his real sister, and that his dad and I will hurt him. It's to the point where our last weekend he was hitting himself then screaming "daddy stop hitting me. Thus is why I should only be at mommy's". He also was making himself throw up and said that his mother told him to do thay when he misses her a million.

It's getting so hard. We try EVERYTHING I stay calm and nurturing because we know it's not his fault. She's doing this to him but at the same time he is almost 6 and should semi think for himself. It's just terrible that the day we filed our petition he was at our house and the happiest kid in the planet. He even said he misses us and hates that he forgets our faces and isn't allowed to talk about us at his moms house. Then we filed and 2 days later we saw him and he was screaming he wants to kill us and we don't love him only his mother and her family does. That he isnt safe here and never wants to come to our house again.

I feel so defeated and honestly don't want to deal with it. I'm pregnant, working 2 jobs, have a 2 year old and then have all of this shit baby mama is causing on top of it. Our family was never perfect but we were happy and now I honestly dread our access time because he doesn't act himself anymore. He acts like a scared zombie.

PS: Court is in 2 weeks and if no compromises then trial will be scheduled. Her response to our 50:50 request was that we should only get SUPERVISED VISITATION AT AN AUTHORIZED FACILITY. There is no basis, she is a terrible example of a jealous baby mama who cares more about her vendetta against my husband than the welfare of their child. And yes child is in counseling.