I was diagnosed last year at age 30. No previous family history in my case. I have 2 children, ages 6 and 3. So far no signs of UC in them, although they are still quite young. I pray they never have it.
I would not let your fear of passing this on stop you from having children. The odds are in favor of them NOT inheriting it. And, if they should happen to develop UC, they will have a parent with first-hand experience to guide them through and support them.