Welcome to the group Amill1516
I'm so glad you've found us and decided to jump in

Unfortunately, the rage is common and miserable . I'm sorry you've experienced it.
Good observation on the people pleasing, I see the same thing in my significant other's (SO's) younger daughter too. She is what we would call the "scapegoat". Her older sister was the "golden child" which has it's own set of problems. Their uBPDmom was enmeshed with the older daughter, the older daughter was perfect and wonderful in the eyes of their mother. The older daughter was also parentified (acted as her mother's parent, confidant and for that matter her sister's parent too). Mom and older daughter were thick as thieves. Both blamed younger daughter for things, both bullied her and excluded her. That's where I think she developed people pleasing... .she wants to approved of, she wants people to like her, she wants to make her mother happy and she wants to be included.
The problem with people pleasing is it's really hard to make all of the people happy all of the time, you end up taking care of everyone else, and then you become resentful.
How do you think you became a people pleaser?
In terms of your mom's rages in my opinion boundaries are key. If she is raging tell her if it continues you will leave/hang up the phone (this is abusive and you don't have to stand there and take it and you don't have to get in an argument either). If it continues follow through (enforce the boundary). I can hear the people pleaser in you thinking but that is so mean or so rude! But really who is being mean and rude here?
Personally I don't think "conversations" about your boundaries with your mother will be very productive (others here may disagree), people with BPD don't respect boundaries and are excellent boundary busters. If it were me I would start thinking about the boundaries I want to create and just start implementing them. Consistent enforcement of boundaries is key and when you start enforcing boundaries things with your mom could get worse before they get better... .this is called an "Extinction Burst".
Link to more on Extinction Burst... .
https://bpdfamily.com/message_board/index.php?topic=85479.0This is my simplified version of what happens when you set boundaries with someone with BPD... .
We've all seen this at the grocery store, a little kid asks mom for candy, mom says no... .kid pouts. Little kid asks mom again for some candy, mom says no again... .kid whines. Little kid asks mom again for some candy, mom still says no... .kid has a full on melt down screaming tantrum (extinction burst). What happens if mom gives in to the tantrum and gets the candy? That little kid has just learned that having a screaming tantrum will get them what they want. What happens if mom doesn't give in? The kid learns that no means no and he gives up. Now this doesn't mean that the next time they go to the store the kid won't test that boundary again, but with consistency it will eventually sink in.
More on boundaries... .
https://bpdfamily.com/message_board/index.php?topic=61684.0https://bpdfamily.com/message_board/index.php?topic=167368.0Again, welcome I hope I've given you something helpful, there is a lot of information, tools and support here, I hope you will explore this site read and comment in other people's threads... .we all share and learn from each other and I'm glad you've added your voice to the mix.
Panda39