Hello and Welcome,
Hardtounderstand! You have come to the right place to learn about BPD and how to improve communication with your daughter. Your relationship was great and now it's not-so-great. That must be heartbreaking.
We are all learning together here, and we are glad you've joined us. Please share more, as you feel comfortable, so we can get a good idea of how we can best advise you. In the meantime, please have a look at this post, pinned to the top of the board - it's got many of our best articles with links to many more:
HOW TO GET THE MOST OUT OF THIS SITE.
You are not alone, we get it better than anyone else can. Things can get better
~ OH
p.s. I see GaGrl was posting as I was. She's right! There are many of us here who want to help.