Hurt my girl, now she's finding it hard to trust me?

I'm quite impressed that after you were so mean to her, you were able to realise that what you did was wrong and even did something about it. it almost made me hopeful that my ex can change too, though you're probably just not a real jerk and it was just an accidental mistake. well she really needs time to be able to trust you again. I think that you should first of all talk to her and describe how bad you feel about your mistake as genuine as you can until you see that she believed that you are really serious, other things you can do treat her right, make her feel that she's special to you, do things that make her happy, find some things that you can do together to make your bond stronger.