Woah woah woah! Don't get too down. It may not have been the healthiest weekend ever, but I can remember a few of my own weekends that ended much worse.
You made a choice to celebrate out this weekend with your mother. There is no good, there is no bad. It was just what it was. And you know what? It'll probably happen again in the future at some point. You may decide that a dinner with family or friends is a special occassion, and you celebrate it how you want. So what?
The lesson to learn is to not make it into a frequent habit.
Once or twice a month? Maybe that's workable in your plan.
Every other day? Well... probably not going to lose much weight doing that.
It can be hard to get back to the healthy ways, though, after a long weekend of eating out. You can do it. No worries