Problem with staying awake!

I daily practice nidra at night before bed and really helped my sleep, but last 2 nights i was tii tired so i really couldn't stay awake... and slept not so well... I read that washing the face with cold water and practicing a little bit of stretching before the sessions can help staying awake.

Do you think that if i listen to very rhythmic music before the session for like 5 minutes, which may give me adrenaline, may help in staying awake, therefore in a better yoga nidra session?

EDIT: the music thing... don't try it, i don't think this may help. Personally i reach the nidra state by having aware breathings, especially deep ones, but i'm going on through this "nidra" thing

Thankss!!!