Sweetie, I don't have personal experience, but wanted to send you a big (((((Hug)))). I'm hoping other mom's will soon post.
The closest experience I have, is of my niece. Her mom (my baby stepsister) died when Brit was just a year old. Her "dad" is an A, 100%. His parents tried to get custody, it was an ugly mess, but Brit...by the age of 3, had her own lawyer, psychologist and the greatest gift...a guardian ad-litem. They are concerned with the best interests of the child....no politics mattered. I don't know if every state has them, but they were a Godsend.
When Brit was still very young, she would see a car that LOOKED like her other grandparents, and scream "NOOOOOOOOO, don't send me to mee-maw and paw-paws...NOOOOO". We were court-ordered to let her have supervised visits with her "dad", at his dad and stepmom's place. They have lots of money, we don't.
It didn't matter...the guardian ad-litem talked with the psychologist (we'd already looked for bruises, any sign of physical abuse...found none) and found that "dad's" stepmom was verbally abusive....all visitations were ceased. We went through he!! to get to this point....she was kidnapped (had a judge threaten to lock up everone in her "dad's" family to get her back), my dad was accused of molestation (totally false, and proven) but we prevailed.
Today, Brit is 17 years old. She's been told (by me) what we went through to keep her from harm...she had no idea. She thought we didn't care. She has her own issues, thanks to a very codie stepmom, but I try to give her a good role model...I'm an RA, she is VERY aware of what I did, when I did it. There were things I wish she had gotten, while growing up....discipline, consequences, etc. but I've had to accept that as much as I love her (I was there they day she was born...she's the closets I have to my own child) she has to find her way. Her "dad" is now wanting to be a "dad". She wants nothing to do with him.
We did what we could. The guardian ad-litem was truly a big help. It's tough, dealing with the courts, judges, etc. but we fought like he!!, and she does know that.
I don't know if any of this will help you, but I do want you to know that there are people here who understand...who have been through similar circumstances.
Hugs and prayers,
Amy