It's nearly impossible to be perfect in health so try to relax a little.
Last night I was running tight on time and was starting to stress that I was not going to make it to the gym for a full workout. I usually like to spend a good hour doing my exercises (cardio and strength training) but I only had about 30 minutes to get in and out. Instead of not going because I wasn't going to be able to do the entire workout, I just sucked it up and did the best I could in the time I had. In the end I felt really good and was reminded that I'm not perfect and that's alright.
If you can't always fit in a full 30-minute cardio workout followed by weights and stretching, it's OK. As long as you make every effort to fit in exercise and eat right whenever you have the opportunity, you're still way ahead of the game. Don't beat yourself up, just move on and enjoy your life.