Supposedly the sigmoid colon is 18 inches, so with 9 inches gone I'm at 50% and you say that you are 100% .
I am sure that taking all of it makes a big difference by comparison.
Three months is truly nothing when speaking of recovery for colon resection and bowel surgery.
Definitely forget the fiber.
Whatever fiber you get, let it come from food, not supplements.
I don't know your age or how naturally active you are, i.e, if you can stay at home every day, etc.
I would slow down, rest more, no exercise like that prior to surgery, just light walking around the house.
At 3 months, some inactivity is not a bad thing to allow your colon to mend and recover. Rest, take naps, sleep and avoid stress.
Get your diet right for colon recovery and eat small, easily digested meals and snacks throughout your day.
You will make it through this but you've got to know that life and bowel activity is going to be different and sometimes challenging for awhile if not a year or more.
No one ever said that colon resection can be a speedy recovery. It is quite the opposite.
Best wishes to you always in this journey!