Oh rats I was editing and changing my response post, but then I guess the window for editing closed and I lost my new response.

I'm sorry about that. I re-read your post and see that you sent the email. Let us know how she responds. We are here to support you.
I am wondering if your partner knows your mom, and is familiar with the family dynamic? Has he seen how she can treat you? Does he understand your fear of her?
I am afraid she will just come to my in-laws house and cry and manipulate them to feel guilty.
Oh dear. I can hear your fear. Stargazer, lots of us here have been known to catastrophize the worst case scenario. However, looking to the future can make us anxious. Looking to the past can make us depressed. Better to live in the present moment. After all, hopefully there is a possibility that doesn't happen... However, when the time gets closer, and if you still think it could happen, making a plan ahead of time (in the eventuality that it does), with your partner, could be helpful.
I hope you are taking good care of yourself right now.

Apart from your mother, are there things about this move that you are looking foward to?
So one one hand, please share any experiences of going back to contact after a period of NC.
My period of NC with my mother was brief - about 2 months. Yours has been longer, and our histories are probably completely different. In my situation, as my fear started to settle, and I started to feel a little stronger emotionally, I very gradually increased contact with her. As I did that, I completely changed how I communicate with her. I use the tools on this site. I live in the same town (10 minutes away), and I am an only child. My mom is 84 and lives independently. She is "needy". I now consider myself LC (about 2X/week which includes a phone call and a short visit). I used to see her almost every day and for longer periods at a time. At one point, she demanded it was our duty to let her live with us. So LC is a relative term. An important thing I learned from my T, was to not communicate with mom when I wasn't in a good headspace. On those days, my T advised I needed to "take care of myself". Otherwise, mom pushes my buttons and I am not in a healthy enough space to respond to those triggers wisely.
after clicking send, my hands started shaking and I got heart palpations. I am really scared of my mom.
I am wondering if you already have a plan of sorts for how to manage once you arrive to the US? I found a really good T who "gets" BPD and that made a big difference for me. This site and the support here has been life changing. I also have a supportive H who read "the eggshell book" and attended T with me (which I encouraged him to do as he also has to deal with his difficult MIL).
I am not familiar with your story, but I am hopeful that there is a path for you to lead a reasonably peaceful life back in the US.