What Do You Do When You Have Become The One Thing Your Friend Hates and Is Scared Of?

My best friend grew up in a home with an abusive father. When I found out about this, I pledged to myself that I would be the friend and male figure that she always needed and deserved. A few days ago, she said something that made me upset over a text message and I wrote back in a way that sounded like I was yelling and mad. I found out today that my text scared her because it reminded her of her dad. So basically now, I am the one thing in the world that I was trying not to be. How do I make up for this? She said she forgives me but I know, deep down, she can’t trust me anymore. How can I gain her trust back? Is there a way to be the good guy again or did I screw up big time and will never be able to fully make up for it? Is there any hope I will be able to be the friend she deserves or have I failed?