Scansion of "Need a nap"

It's lunchtime, drowsy, sitting quietly here.
o     B    o      B  o   B  o     B-o-   B
A warm burrito's drained my brain away,
o  B    o  B o     B      o   B   o B
digestion slowing thought and busy work.
 o B  o     B o     B     o    B o  B