Can I file a restraining order against the sherrifs office?

To get a protection order you must be able to show the judge that you are in 'imminent danger'.  If you can do that the judge might considerr granting a protection order but it seems unlikley frankly.  All law enforcement offices have an 'internal affairs' department where you can complain about the actions of specific officers. You might try contacting them. Without knowing the specifics of the police harassment, it is hard to answer further.