Good god, I swear worked for the same DM.
My advice is this - Don't go to HR until you have another job lined up or are willing to leave. The idiots here posting this advice don't know their ass from their elbow.
HR is career suicide - don't think for a minute they are here to help you. They will reach out to the manager and talk to him of the "anonymous" complain and he will know it was you. He will fire you in less than 6 months.
There's only one thing you could do. Brown nose him. Sit down and talk to him. Give him the corporate lies he wants to hear about how you are working hard growing your territory and apologize for anything and everything. You don't have to out run the bear you just gotta out run the other guy. Aim to get on his good side until he finds someone else to pick on.
