No-show to own baby shower.

I don't think I can go to my baby shower tomorrow. It has been the worst time in my entire life lately and nobody seems to understand that. 
I begged them never to throw me one, and once they started, to cancel before it was too late (a long long time ago before they had even paid for a thing) and they insisted on keeping it going. 
Physically I shouldn't be doing anything stressful (high risk), I'm on modified bedrest and the stress is absolutely making me feel worse and making my contractions and BP worse as well.
What on earth do I do? I am so miserable about this. I don't want to be the biggest loser on the planet but I don't want to put myself in a situation that makes me worse.