I'm sorry you have to go through this. I know how worrisome it can be. Please remember though that the majority of abnormal Paps are caused by many other things besides cancer. (What level was your abnormal Pap?) Also, just because there is nothing up in there, it doesn't mean that it's automatically cancer. Infections, douches, hormonal imbalances, dysplasia, and many other things can cause abnormal Paps. I'm sure your doctor is just following the recommended procedure in doing the colposcopy, since it's always better to see if anything is going on, just to be on the safe side.
I also had a hysterectomy five years ago. In May of 2005, I had my first abnormal Pap. (I hadn't had a Pap in the three years after my hyst because my doctor told me I didn't need them anymore.) In August, I went in for a follow-up Pap and it was abnormal again. Long story short, I was diagnosed with moderate and severe dysplasia. My mom had just died, and I didn't get treatment at that time (which was stupid!)
After frequent follow-up Paps over the next year and a half, I was diagnosed December 2006 with carcinoma in situ, cancer which hasn't spread yet. I had laser vaporization surgery in May, and all of my follow-up Paps since have been normal. I have to be monitored every three months for two years, but my oncologist is confident that all of the cancer is gone.
Luckily, dysplasia and cervical/vaginal cancer are very treatable and very slow to progress. So, while it can be upsetting, it's not nearly as bad as it could be.
Good luck and please let us know how you're doing and what you find out. My prayers are with you that everything will be remarkably unremarkable.
Oh, and by the way, if the doctor does a biopsy during the colpo, have him tell you right at the moment he is going to take the sample and at that moment, cough. You won't feel a thing. (But tell him what you're going to do first, so he'll be prepared.)