1. I'm not sure what your handicap/disability is, but you may want to contact the hotel and let them know you require an ADA accessible room with a couch. My guess is there is an easy fix to the problem you are describing.
2. If there is not an easy fix, we need to know more about the agreement you want to rescind. Did you pay money for this package? Are you okay with forfeiting that money if they refuse to refund it? Did you sign any agreement that imposes any other obligations other than you paid for the package and have to attend the presentation, meaning did you sign some agreement to buy a timeshare? Sounds like you did not, but that needs to be known.
3. If you have no further obligation other than to show up or forfeit your money, then obviously you don't need to show up. And if you do show up, do not under any circumstances sign any contract to buy anything, whatsoever. Ask them when they arrive how long you have to stay, and keep an eye on your watch. When the time comes, say "thank you, it's time, have a nice day," and leave. Personally, I always have nice conversations in timeshare presentations, but you sound like you might be at risk of getting swindled, coaxed, and prodded into signing something you might regret. Please don't.