Based on Virginia law pertaining to the protection of mental health employees from violence by patients in mental health institutions, and codified at this link, the degree of liability of your employer depends on whether they knew or should have known whether a particular patient is likely to be violent, or has made threats previously. The relevant quote is as follows from section B:
A mental health service provider has a duty to take precautions to protect third parties from violent behavior or other serious harm only when the client has orally, in writing, or via sign language, communicated to the provider a specific and immediate threat to cause serious bodily injury or death to an identified or readily identifiable person or persons, if the provider reasonably believes, or should believe according to the standards of his profession, that the client has the intent and ability to carry out that threat immediately or imminently.
Therefore, the degree to which you can legally recover would depend to what extent your employer is forewarned about the demeanor of this particular patient. If you had any previous interactions with this particular person, documentation of their language, conduct, and / or mannerisms would be your best friend to help evidence that this particular person has exhibited threatening / violent behavior in the past. Hence the part on where employer should have known comes into effect.
If your employer did not warn you about such possible violence from this patient and they should have reasonably known about it, they probably did not meet their degree of due care required under the law to avoid liability under section C (2). Again, documentation (or the lack thereof) if your friend here.