Guilt

Stop classifying food as healthy or unhealthy. View them as very nutrient dense or less nutrient dense. See them as a way to hit your macros and still enjoy tasty treats. One day of going over your calories isn't going to stop you in the long run, just like one day of eating well per week isn't going to help you reach your goals. It's the overall sum of what you do and not a single day.

I don't view eating as something to feel guilty over unless you stole the food from someone else.
Don't make it a dramatic emotional event.
If I go over my calories I think "why did I do that?What can I change to better reach my goals in future?" Was it because I didn't have enough protein, is it my period, am I tired or stressed? Is my calorie goal too restrictive? Did I go over my maintenance calorie level?
I'm not perfect. You aren't perfect. Probably everyone here goes over their calorie goal sometimes. You log it and move on.

I also don't call food healthy or unhealthy. That is vague and meaningless to me. Does the food help you meet your nutritional needs that day and leave you satisfied? Is there another food that could do that better for you?

A lot of these issues are solved by pre-logging my food and not being an emotional eater.
If you are an emotional eater work on developing new tools to deal with your emotions.

It helps me to do the arithmetic in my head & understand what the over-goal implications are. Usually, they're manageable. But if I don't like the implications, I know what to do.

If you're over goal, but below your estimated TDEE/maintenance calories, you didn't gain any weight, you just delayed reaching your final weight-loss goal (by less than one day). If you ate over maintenance, it matters how much over, of course: If you ate 3500 calories more than maintenance, you gained a pound. How much delay is that? However long it takes you to lose a pound at your current deficit (i.e., a week if you're losing a pound a week). If you were over maintenance, but less than 3500, you can figure out what fraction of a pound you gained, and how much delay that is.

Then you decide how important a problem that delay or gain is to you. Probably you'll find that being a bit over goal, maybe even a bit over maintenance, is not the end of the world as long as it's occasional/rare. It may even be a good decision, if it was a truly special occasion, like your birthday or Christmas. Just get back on your healthy routine as soon as possible after you realize you're off track. Don't let one over food/snack/day/etc. become an excuse to give up. Stay persistent.

I think lounmoun up there gave you some good advice, too, about using your diary as a tool. Maybe put some things in the notes daily, too, that might help you understand how your body works - like how much sleep you got, that sort of thing. So, if you went over goal, why might that have happened, and what might you do to minimize the risk of it happening again: Sleep more? Eat more protein? Get a solid breakfast? Have a small snack before you get famished instead of going wild later one? Plan ahead better so you have more calories available to eat at a special event? Fit in some extra exercise to earn more calories for the weekend? Etc.

Try to keep the drama out of it - it just isn't helpful . . . and it sure isn't fun. Try to turn the weight management process into a science fair project, or a detective story, or something other than a morality play, so you can make rational decisions about it. We all have to eat. We're all going to eat a range of foods. The foods aren't good or bad. We just need to figure out how to eat so that we get solid nutrition, feel good, and (once in a while) get to celebrate special occasions with the people we love.

I don't know if you are religious or not, but I think when I wake up, "Thank you Jesus for giving me another day to do better." I don't dwell on it, it will kill you, quicker than the extra calories.