Don't feel bad. You ate some high calorie stuff, you didn't do anything really wrong. It's just food and this is just 1 bad choice you made.
Good news: you are lucky enough to have the opportunity to make your next choice a healthy one. More good news: no one expects you to be perfect all the time. In fact, I've been working on my healthy lifestyle change for over a year and have made plenty of poor food choices in that time. That hasn't stopped me from losing over 50 pounds! Strive for progress, not perfection.