Hi,
I'm sorry you are faced with this life changing medical condition. You must be very scared, especially having children and so many other concerns. I had a complete colectomy and a J-Pouch installed when I was 20 year old (27 years ago). Maybe surgery is easier to handle when we're young and have less people relying on us to be well.
I know this is not the case for many people on this site, but my quality of life completely improved after surgery. The first surgery is major, and recovery was painful, but pain medication works and recovery can go as expected without complications. For me living with UC was more painful and debilitating than surgery, and life with a J-Pouch is not at all like the frequency, gas, etc related to an illness and disease. It's just the way the J-pouch works and not a result of something being wrong. There are certainly adjustments and precautions you will have to make to minimize things like skin irritation, dehydration, watery stool, for example. (The second procedure is a lot easier than the first.)
Everyone is different, I know, but my surgery was completely successful at the time. I hit some bumps in the road over the past 27 years, but nothing nearly as bad as the ongoing complications some of the members of this site have had to endure.
Hope this alleviates some of your fear.
Shannon