My goal is to be within a healthy weight range and to develop long term healthy habits. Exercise is not an issue normally. Every once in a while I get off track but I've exercised regularly for 30 years. It's all food!
This week I added a goal of doing 250 minutes of fitness. So far, so good as I'm on track.
I've had so many occurrences of regain myself. Definitely stay away from the scale for the time being if you think the potential for it to show a regain will derail you. (Me: I tend to get discouraged and use it as further impetus to self destruct rather than correct my behavior.)
Just get back on track right now and use the slipup as a learning experience. It's a learning opportunity if you use it to make you stronger for the future. I know - easier said than done - but you can do this.