Hi
explain 
I join
Faith in welcoming you to bpdfamily!
Many of us here struggle with the line between enabling and supporting.
Faith hit the nail on the head -- if a person is capable of doing something, s/he should do it. As you say, the fear that our pwBPD (person with BPD) may self-harm or respond in other unhealthy ways keeps many of us stuck.
A thread was started some months ago where you can see how others have learned to let go. You may find it helpful so I'm posting it here:
How do you cope with letting go?Feel free to post your own thoughts, struggles. Let's talk about it!
~ OH