Thanks for writing in to Healthcare Magic!
The change of mood, deprssion, lack of concentration can be expected with Depot Provera
but the other things like feeling tred and unwell and fast heart rate
are unexpected sequelae.
I think yours nurse is right you may be having some viral syndrome
like resp. infection or infectious mononucleosis
If you have any further query please let me know I would try to answer it for you.
Wish you a great health!