For The Last Four Days Inthe Afternoon I've Become Soo

For the last four days inthe afternoon I've become soo sleepy to the point I am incapable of preparing suppervror family. I simply cannot feep my eyes open. I have a metronic spine stimulator and it stop working @ 2 weeks ago. I'm scheduled to have the old unit replaced 4/14/2016. Could this be an issue. It's extremely frustrating. Any insight would be appreciated. Thank you kindly.