Hi Jsab13,
Welcome to the BPD Family

What you are describing sounds very familiar. Have you explored the site? I found it amazing how similar all of our stories are. You are not alone.
She tells me, and told me that night, that I’m a bad selfish person, I’m ungrateful and never appreciate her. She always says I don’t answer the phone enough and gets irate if I wait a day to call her back or basically do anything that isn’t 100% on her schedule.
This sounds like FOG (Fear, Obligation, Guilt) or emotional blackmail to me. This is a big tool used by folks with BPD and I think it really helps when you can start recognizing it when it's happening. I find when you can recognize when you are being manipulated it's easier to not take things personally and when you don't take things personally it becomes easier to set and enforce boundaries (which is a key tool to our own happiness).
More on FOG... .
https://bpdfamily.com/message_board/index.php?topic=82926.0My father left when I was thirteen and I, being the oldest, ended up parenting my brother and my mom through her divorce and later when she felt like she didn’t want to deal with my brother and I
This sounds like parentification... .when a child is put in an adult role (this is inappropriate). My significant other's older daughter was put in this role by her mother once her mom and my SO separated. She was emotionally care taking her mother, cooking, taking care of her sister... .basically filling in for her father who left. Does that sound familiar in your case?
More on emotional incest... .
https://bpdfamily.com/content/was-part-your-childhood-deprived-emotional-incestSince it sounds like you are new to BPD I'd like to suggest a few books that you might want to check out.
These first two are about BPD in General and I suggest getting a good basic grounding in what BPD is before reading my 3rd suggestion which is specifically about BPD mothers... .
Stop Walking on Eggshells: Taking Your Life Back When Someone You Care About Has Borderline Personality Disorder by Paul Mason MS, Randi Kreger
Overcoming Borderline Personality Disorder: A Family Guide for Healing and Change by Valerie Porr, M.A.
Understanding the Borderline Mother: Helping Her Children Transcend the Intense, Unpredictable, and Volatile Relationship by Christine Ann Lawson
I'm really glad you've found us, there is a lot of information, support, tools and ideas to be had here.
I hope that I have shared something helpful.
Panda39