Aim Not for Perfection but to Please Yourself
You aim for perfection and then get upset when you miss the mark. And that's negativity you just don't need! We all make mistakes (it's human!), but you can't let those slipups get the best of you. Don't get discouraged if you fall off your diet or miss a workout — and certainly don't throw in the towel! Plan to do better tomorrow: Do an extra 15 minutes of cardio and a few extra reps of each exercise in your strength-training workout, or walk a little bit further.
Remember: One failure doesn't have to stop your progress or take away from all you've achieved until then. Put in a little extra work later, and relax and enjoy your day.