I was hit in the face by a woman at my job, she report me to our HR and I was fired without asking what really happen, what should I do?

This women at my job hit me in my face over a misunderstanding, Yes I was trying to explain to her what happen then while explaining she said I should hit then I try to continue explaining myself some more then while talking she out the blue hit me in the left side of my face hitting my glasses as well. Now I am having headaches. Then she went told HR department and now I am fired with even asking me what happened.