I am so sorry for the loss of your sister.
I can only tell you what I told myself when I was in the hospital recovering from emergency surgery and waiting for pathology to confirm the cancer diagnosis and stage me: try not to freak out before you know for certain that you have reason to. And even if you get bad news, allow yourself to wallow for a few hours and then put those thoughts out of your head and concentrate on surviving.
I know that is hard to do. Right now, you should get out of bed and try to do something fun and positive with those wonderful kids. Accept support from people who are caring and positive, and don't let people boohoo over you and bring you down.
Bear in mind that even if you do have colon cancer, the cure rate, especially for the earlier stages, is really good, much better than it used to be. The medicine is evolving quickly. You are young and strong. You can do this.
Hugs, and best of luck.
F, 64 at DX CRC Stage IV (or "3 1/2" per Dana Farber consult, LOL)
3/17/18 blockage, emergency surgery, r hemicolectomy
11 of 25 nodes
5 of 5 mesentery nodes, matted
0.5 cm sub-capsular liver met removed
pT3 pN2b pM1
Neg CEA, neg BRAF, mut KRAS, germline mut ATM
dMMR, MSI-H, Neg for Lynch
5/4/18 FOLFOX started
Added Neulasta 6/28/18
7/9/18 CT scans show no masses or enlarged nodes, 2mm indeterminate lung nodule