I think problems at night are normal for UC. I used to have big problems as soon as I layed down. I'm guessing that being horizontal is what triggered it. Just like 40&crashing, as soon as I rolled over, the pain came back in a wave centered in my gut. Awful. Like you I was getting up 3-5 times per night, couldn't sleep and was tired all day.
I did find that a heating pad on my stomach helped.
I have been in remission for over a year and don't have that problem anymore, thank God. I started taking an herbal supplement that has really helped but the cramping was the last symptom to get under control. Also, I take psylium every morning and I think this helps also. Mary