In all likelihood it probably is mental health related... however calling/seeing your doctor would definitely be a good idea.

I don't think a trip to the E.R is necessary, as if you had any sort of serious health problem, there would be other symptoms. I assume you are well apart from the wakefulness physically?

Anyway a doctor will rule out any other more serious causes if there is any cause for concern & will probably prescribe you something to help you sleep short term. Certainly a good idea to tell your psychiatrist too.

I hope you manage to get some rest soon though.