Walmart complaint: employee

I am filing a complaint concerning the Pharmacy Manager Karen Richardt. I was hired in July and its been a constant case of bullying, belittling, and accusations of wrong doing that Karen has accused me of being involved in. I have been told there are active investigations going on that have gone above store level and yet have not been told what the status of these investigations is. When offering my side of the incident. I was told she did not believe me and continues to write me up for incidents that i didnt realize i did. I was hired as a pharmacy cashier and now have done some technician work. Karen has told me that I am the reason that her pharmacy rating are down and in a separate incident referred to me as brain dead and reminds me that she will terminate my employment if i dont improve .When i ask her what i need to improve in. Karen says to refer to my job duties and you should know. Karen does very little to motivate her employees and when questions are asked on procedure matters. The response is you should know how to do this. She tends to play favorites to those she likes and downgrades the ones she doesnt. The work environment is hostile and negative when she is around. Managers also need to have people skills as there are all different types of ways to learn. She tends to get frustrated easily and lashes out. I am an epileptic and this kind of stress causes my seizures to be more active. I also have a disability called aspergers which although i function as everyone else, I learn slower and repetition is very good for me. I go to work everyday and only want to do my job to the best of my ability. There are laws to protect employees from this type of harrassment and I just want to do my job and be appreciated for the job I have done.