Meadow: Welcome. You are with friends here. I am in a similar situation and know people who are in ones much more like yours. It is hard. It can change. My ex won in his bid to prevent me from moving with my children, even though he is frequently out of the country for 6-9 months at a time (with little visits in between).
We had been divorced for 8 years and he is remarried.
My children are mostly with me, and do great when he is not around, but when he is, he is very possessive of his time with them and they admit to being afraid of him, feeling sorry for him, whatever he happens to be manipulating them with at the time. Add to that, the fact that however flawed, he is their father.
I was very afraid throughout the trial. I met a former colleague who was accused by her scumbag lawyer ex of PAS (the syndrome of which you speak). She was devestated. Her story scared the hell out of me, as did the multitude of others you can read about all the time.
I visited the website thelizlibrary.org frequently. There is a lot of information on this horrible state of things for custodial mothers....it was informative, and I do recommend it (to my lawyer!) but after a while, I realized that it kept my focus on what was negative and going wrong.
I am actually thankful I lost my case, because I HAD to figure out why things kept going "wrong" for me in my life. I came to realize I created it. First by marrying him and having kids with him, second by staying scared of him and most importantly, by focusing on how "awful" HE made things for me. I had to change some core beliefs about myself first(I was not worthy, pain is BAD, I have to give it all away to be a good person).
It was a long hard road, and still is, but I am happy on this road. I know how to let go of that negative/scary stuff and focus on what I want. I know I am creating it every moment. He will not change. I have, and continue to. He does not have power over me. I have power. I chose to stay with my kids. I did that. I choose to be happy no matter what. I choose to be the light for my children. He doesn't get to tell me how to feel.
Since I have changed, my children are much happier with me at my home. They want to be around the happy parent, the one who isn't miserable. The one who can find happiness no matter what the circumstances. They need to learn that somewhere. N's want us to take their pain. They get very upset when we don't and they have to deal with it. When they get us upset, it alleviates some of their pain for them.
THIS for me is the hardest. He could drop off the face of the earth for all I care, but he USES our children to punish me. I understand easily, how not caring about what he does removes his power....but I have to care what he does to my kids!!! Thus, we are stuck with these parasites forever. But it doesn't have to be bleak. If you can find ways to see what is good, and learn from/laugh at what isn't...you can heal.
This message board has been such a place for me quite frequently.
Seek ways to find happiness within. You will then be able to create what you want out of life , instead of focusing on what you don't want. You get what you focus on, or thoughts become things. Operative concept for me, was how to embrace and subsequently let go of the negative without squashing, denying or ignoring it. Ask for help form people, from the universe/god. You will get it.
I have been right where you are, lots of us have. It can be done.
I wish you light.