Welcome Mountainflower!
I'm really glad that you have found us here at bpdfamily.

You are among a group of members who will understand and be able to offer helpful thoughts to you. There is a lot of information available at our site, and it can be overwhelming, so take your time. The important thing is to not only read, but also
to absorb.
I bumped up a thread about in-laws that I thought might be helpful to you. It has a 'star' on the left side. When you are able, take time to read through some of the posts by others who are struggling with situations similar to yours.
I'm really glad you are in T.

How did you feel when you read about BPD and found that it sounds similar to what you see in your d-in-l? Were you relieved or did you feel worse?
One important aspect to keep in mind is that you cannot change or control the outcome with someone else. However, you can work on yourself and how you interact with her. It sounds as if she is splitting you black from what you shared, and that you've lost favor in her eyes.
Here is a link about ending conflict:
https://bpdfamily.com/content/ending-conflictWhen you go to this link, there are quite a few more green boxes on the right that you may also find helpful, and there is a lot of excellent information there.
Please stay in touch and let us know how you are doing. The holidays are especially rough when a BPD is involved.
Wools