I remember those days awaiting the breast surgeon appointment. I didn't sleep more than an hour or so and had many tears (especially in the shower).
The waiting and unknown is the worst. I must say I did feel better after the breast surgeon appointment and once I had a treatment plan sorted. Not saying there weren't more tears nor more sleepness nights and even now, 12 months on I still sometimes have them.
You will find you have more inner strength than you ever thought possible and strangely, even though different cancers and different treatment you and your sister will have a common bond that is rare. You will both understand how difficult this treatment can be, and how scary it can be.
Lean on each other when you can...and don't be frightened to shed a tear in front of each other. You my dear have us though, to just let off steam to and ask questions. A site for bowel cancer I don't think exists.
I hope all goes smoothly for you and please let us know how you go. Take care. Kath x