Hi valleymom and welcome! I am so glad you have found us - there is much support and valuable information on this wonderful forum. It has helped me immensely in my relationship with my BPD dd21, as well as in feeling that I am not alone in this, and that I am not to blame.
If you haven't already perused them, the lessons on the right hand side of this page are a great place to start

How old is your BPD child and has he/she been officially diagnosed? Are you comfortable sharing a little more information about your situation and what brings you to the parent forum?
We look forward to hearing more from you, valleymom. You have come to the right place for empathy and understanding! You are not alone. MomMae