My mom is my boss

When I graduated highschool last year, I decided to quit my job I had to work for my mom because she needed to hire people and no one was applying for the job. She’s the manager of a local fast food restaurant where I live. At first it was great. We trained me, and I’ve always done very well at my job. My current boyfriend was already working for her for a year before I started. Shortly after I was hired I decided to move out and get an apartment with my bf. And since I’ve moved out, my mom has gotten a lot harder on my bf and I at work. She’s always holding us to a higher standard than our other coworkers and a lot of the time will yell at us and degrade us at work. I usually put up with it because she’s only like that at work, outside of work she’s just like how she’s always been. Loving, supportive, etc. well yesterday my bf mom and I were all working together and my mom had been yelling at us all day and blaming things on us that were her fault. My bf eventually was like hey, you need to calm down, we know you’re stressed but we’re all working our asses off and we don’t deserve to be talked down to. He was very calm and nice about it (honestly more than usual), and she flipped out, started screaming and went in the back, punched a wall and then just left us in the middle of lunch rush. She came back 20 ish mins later, sent my bf home and then was just yelling and crying the rest of the day. Before I got off work I told her that I’m sorry he hurt her feelings but that he was right, and that we don’t deserve how she treats us and that we just don’t like how she talks to us. I was really nice about it, I told her I love her but we are hurt too. After that she wouldn’t talk to me. When I came back to work again (my bf and I have been working 2 shifts almost every day, we’ve both been getting lots of OT), my coworker who had been there with us all day and had heard all of it, told me that I made my mom cry and that I’m the reason all of this happened (that’s what my mom had told her). I just don’t understand what I’m supposed to do!!! My mom is our manager, literally her only superior is the owner of the store. She should be an example instead of talking down to all her employees. I texted her and apologized for hurting her feelings and told her I love her no matter what and she just said “it’s fine”. Am I supposed to just let her bully us? She’s not like this at home. But she’s always been so mean to my bf that now he won’t even go with me to family things anymore because of her. And my bf is mad that I’m letting my mom walk all over me. I just feel like I’m being made to choose between my mom, bf, and job. I need advice 😭 I’m only 19 and I have no one to talk to about this.