If she is that distressed, I would let her out for a while. Maybe she will feel better. I wonder if that E-collar is bugging her. Have you tried not using it? That might settle her..maybe she is trying to get it off? Just a thought!
They might have soft collars at Petsmart..you can ask them!
If you take fabric that is longer...and then gather it to fit her neck, it will be a bit flimsy..but it sticks out .. hard to describe, but with the gathers it is a bit firmer.
There is a picture of one here:
http://www.petfooddirect.com/store/product1.asp?pf_id=11140604&affiliateCode=PF012803 &cm_ven=Performics&cm_cat=Yahoo%20Search%20Submit% 20(SMX-NSO)&cm_ite=DDI%20Link&cm_cat=k115513
After she gets settled, she will probably mostly eat and sleep. That is a typical senior day. They are not normally frantic...I am thinking it could be the collar...or she has pain? I don't know. Hard to say.