I have become the "wicked stepmother"

My step daughter lashed out at me today and it's really hit me hard. I've been raising four kids my twins (F15) and my step daughter (F15) and my four year old son. I'm a career woman and I'm on my own I lost my husband two years ago and I've been struggling with four kids.I have come to realize that I created the same environment that I grew up in and I didn't even realize it. I didn't realize I was favoring my biological children over my step daughter and I've come to realize I've been giving her an unfair amount of work. I've also been made aware of bullying in the house.I'm not good at expressing my emotions (I've been nicknamed the Ice Queen at my job) and I can be bossy. My stepmother was very cruel and so were my stepsisters I still bend over backwards for them. I just do not know how to make an amends with my stepdaughter because I'm not good at expressing my feelings in a healthy way.I loved my late husband I still do and he was the only person I could be vulnerable with. My childhood made me have to hide my emotions so I often come off as a very cold person with a temper. My step sisters often made fun of me growing up whenever I would cry so I don't cry around others but whenever I'm alone I think of my late husband and all I do is cry and I hate that I've hurt his daughter by treating her unfairly and I don't know how to fix it.I looking for suggestions on how I can improve my relationship with my kids and how do I fix the dynamic between my children? via /r/Parenting https://ift.tt/2olADLH