I told my boss I wanted to leave and...

okay! so long story short I've been an assistant at a 2 stylists salon for 3 years now. I do a lot. I'm honestly more like a person assistant than anything and I've been fed up. I've had no freedom to go to school bc she has me working 13 hour days 4 days a week W a half day (6 hours) a week. and pays cash. which she has jipped me on many times before. I'm 20 years old and would like to go back to school and actually have a real job. today she pulled me aside and I told her the honest truth. I would like to consider finding another job soon & this wasn't for me. She FLIPPED out. told me I'm being "immature", that I can't go anywhere else because im "uneducated", I'm a "bitch acting like a 2 year old". I was doing stupid shit ladies like going out and returning clothes for her but she wouldn't like me to take time off to school or let alone BE SICK! so toldme today would be my last day and I should just leave for the day. so do and she texts me this because I toned, didn't even DYE my hair. I feel so disrespected. am I over reacting?