Welcome!
I am also currently estranged from my BPD-mother (3 weeks this time, also probably the 17th time in the last 24 months). I completely understand the feeling of being "free" but also "hurting" at the same time. I am also newly in therapy.
One thing I have done before that hindered my strength was go over and over the past. You mentioned that you are realizing all that you have had to endure your whole life. Right there with you. Reading self care books/articles made me identify all kinds of abuse I had no idea that were actually abuse at the time. There is one important thing you need to realize also
You did not deserve any of the abuse that happened to you.
Currently, the goal is focusing on self-care and setting boundaries. I got the self-care down, but I have no idea what to do setting boundaries which is why I am here.
Tips for self care-
Put affirmations on your bathroom mirror. Read them out loud every time you take a shower. If your mother calls you ugly, write down "I am beautiful inside and out." If your mother tries to make you believe you are a failure, write down examples of things you are actually proud of. They can be small things like "I have a beautiful garden." Whatever YOU have done or created that YOU are actually proud of is valid and means you are a success. Read them out loud every day until you believe it.
I wish you peace, , and healing.
-AG