1. Do NOT talk to your supervisor first.
2. Contact the Employee Assistance Program and request an immediate evaluation by a psychiatrist.
3. File a work comp claim if you haven't done so already, contact HR or your employee handbook for where to go.
4. Then talk to your supervisor.
I cannot give our specific legal or medical advice per the TOS of this forum, but in most cases, this is a work-related injury and should be treated as such, just as any other physical injury would be treated. Depending on your state laws, you are likely entitled to treatment and time off through your work comp policy. If you have your own malpractice insurance, you may also need to let them know and may be able to obtain representation through that policy. If you don't have your own, please research available policies and make that investment.
5. If nothing comes through for you via the above, you are still entitled to FMLA leave, although it is not paid.
PM me directly if you need to talk. I haven't been through it myself, thank heaven, but have helped others in similar situations.