Sorry to hear this Hambeak. Cancer of the colon is one cancer that usually is taken care of with a good amount of success.
It usually involves surgery and has a high recovery rate. Don't give up now, because you will need to go through a few tough times either way if it is terminal or not.
This sort of thing is very frightening no matter who you are or what you have had to go through before.
Being a total mess in a situation like this is not unusual. It is a normal response to an incident that we would all be upset and confused and angry.
Life is difficult no matter who we are or what we face. No one gets a free ride in life. I guess just hang in there and support each other, do some plans for the future to handle this illness and the results what ever they may be.
If there are some trips or any other thing that you planned, try to do them now and enjoy what you can do today and consider the use of chemo and or you'r quality of life with or without chemo and the expected life span if this a terminal illness.
You may decide to omit the chemo and enjoy the time you have left. Or take the chemo and hope for the best.
Take care of each other and show your love by actions. This will be a difficult thing to go through.
I know. I just went through it with my wife.