I'm trying

I don't know how long you had been doing well, but keep in mind:
- the majority of your days determines your outcome, it's okay to splurge occasionally
- depending on how much you went over your goal and what your selected weight loss rate is, eating over your goal could still be a calorie deficit for the day. For example, if you chose a weight loss rate of 1lb per week, and you ate 250kcal above your goal, you'd still be in a deficit of 250kcal (equivalent of 0.5lbs loss per week)

Spend a short time thinking about what went wrong (if anything) and what you could do to avoid this situation:
- lack of planning -> improve planning
- your plan is too hard because of a low calorie goal -> lower your selected weight loss rate to make your plan more sustainable
- your plan is too hard because you can't eat what you like -> find ac way to include your favorite foods in your plan
- etc

And then move on, don't beat yourself up about it 🙂 no one is perfect, all we can do is our best and learn from our experiences.

One day over calories I have been counting calories for a few years now and one day no big deal. hell I have logged over my allotment for days and weeks before it's ok.the past is the past its behind you now.

Pretty good, on average over time - that will work fine. One day is a drop in the ocean of life. Furthermore, if you're averaging under your weight-loss calorie goal for the week, you're still losing weight, just a little slower than you'd targeted. You don't have to be perfect.

It's fine to strive for hitting goal every day, but if you're there most of the time, and exceptions are small magnitude and rare, you'll make decent progress. Agonizing over it afterward burns no extra calories, and tends to feel icky. Why do it?

Lietchi's right: If you don't want a repeat, just spend a few minutes thinking about why it happened, then revise your plan going forward to reduce the chances it'll happen again.

I'd add that it's OK to decide it was worth it, in your overall context. If I eat extra calories on a rare special occasion, for example, sometimes that's worth it to me. As long as it's rare, NBD, IME.