I agree, hang in there for now. Do you have any sick leave you can take until you find out about the financial assistance and meds? You can always tell your employer, but you can't always take the information back away, you know? I think it's great that you are so concerned, but realize that you might be jumping the gun at telling at this point. Sure, you are "off" a bit, but everyone gets that way. If they notice, then say so... that you're feeling a little off lately and have seen a doctor (or have an appointment) to check things out.
TC!