if you don’t want to sleep on a dog-pee-covered recliner, seriously, try the wedge pillow!:
http://www.amazon.com/InteVision-Wedge-Pillow-Quality-Removable/dp/B009HHLBKK/ref=sr_1_1_s_it?s=hpc&ie=UTF8&qid=1461692146&sr=1-1&keywords=InteVision+Foam+Wedge+Bed+Pillow+(25"+x+24"+x+12")+with+High+Quality%2C+Removable+Cover
you can sleep in your regular bed (with clean sheets, and the ice machine running next to it, all night long, to help you be comfortable enough to sleep.)
this is what I used for several weeks, and it was great.
I was supposed to wear the sling for a month as well, though after 2 weeks when I went back to work, I would take it off while working at my desk.
I also had work done to correct some minor rotator cuff issues, and that procedure was simple and had virtually no recovery time or impact to my life. That darned biceps tenodesis (and they did reattach mine) was the big deal.
Hang in there! I know it’s scary. Mine wasn’t causing as much pain as yours sounds like, and in retrospect, I could have/should have delayed the surgery for a year or two, but couldn’t do to my job, long story. If you are debilitated by pain, you need to get it resolved. The recovery will suck–but try to focus on the long-term picture of pain free days without worrying about when that knife pain will strike!