<human>: I recently started working shift work at my job due to some "restructuring" of the department where several people got laid off, and I've had a hard time adjusting to going back and forth between night and day shifts. I picked up a variety of sleep aids to try and transition a little easier.

One kind in particular was overly effective so I haven't used it more than once or twice. I put it on my night stand and forgot about it for awhile. Two weeks ago I had to go the dentist and get a filling done, and it's been causing me a lot of intermittent pain at night. I woke up at 3 a.m. with my entire face throbbing, so I reached for my Tylenol and water beside the bed. Without turning the light on or using my brain at any point, I took two pills and went back to sleep shortly after.

9 hours later I woke up at noon. I looked at my phone right away and saw several missed calls and texts from my boss and coworkers, wondering if I was okay and when I would be in to work. I freaked out and called my boss right away, I didn't even have a good excuse other than "I overslept" because that's all I knew had happened. I felt terrible and so confused. 

As soon as I walked in to work my boss called me to her office, where she had a corrective action form already filled out and ready for me to sign. I've never been written up for anything in my life, so I broke down in tears and begged her not to do this, as I know the managers are looking for others to lay off before fiscal year end. But I had no good excuse for being 3 hours late to work, and she was really pissed off that all I could give her was "I overslept". My coworkers were also quite mad at me for it as well, and didn't speak to me at all that day. 

It wasn't until I came home at night and realized that my Tylenol is on the dresser and it's those fucking sleeping pills on the night stand, that I realized how I fucked up.

Can you provide a brief overview of the text?
<bot>: mistook sleeping pills for Tylenol at 3 am when I woke up in pain from a recent filling. Was 3 hours late for work, got written up by boss and shunned by coworkers.