Don't beat yourself up about it, we've all done it.
But be proactive now.
Start on some good probiotics, like VSL#3, cut out the dairy and wheat from your diet and you'll see it will make a big difference.
IMO, Don't take Ensure - it's loaded with crap, junk, HFC, and sugar.... all bad for UC.
L-Glutamine is good, but must be taken in good quantities - 15 grams daily.
And drink lots of good water.