Emotional Eating
There is nothing wrong with craving foods that are perceived as 'bad' or unhealthy. Don’t feel guilty about having those cravings, you’re human.
If you're stuck in a constant cycle of binge eating in moments of stress, sadness, or anger for example, another coping method needs to be explored, instead of using food to comfort yourself and numb those uncomfortable feelings.
The reason you feel guilty after eating off your diet plan, is probably because it's not what you really needed mentally and emotionally (and physically if you think about it). The junk food was just a quick fix, which gave you the instant gratification you craved, but it really didn’t help with the root cause of your stress/sadness/anger etc. And ultimately wont contribute to achieving your body composition goals.
Ask yourself:
How much it will affect your progress?
How urgent is your goal?
Is this in line with my goals?
Part of the solution could even be implementing a re-feed day where other more 'fun' foods can be enjoyed that day within reason and with planning, so there is no binging, guilt or a huge impact on your results.
An experienced sports nutritionist can help with all of the above. If your goal is to get lean, this involves more than just being handed a diet and you going off and following it, there will be hurdles, and as long as you really actually want the goal you say you want, you will be able to work together on achieving that.