Fast weight loss after vacation????

Ok so I’m 16 a female. I have bad anxiety and tends to get anxious a lot and pay attention to a lot of things. I just made a post about how I gained like 6 within 2 days of cruising. I gained 9-10 pounds in total after the cruise. I got back Midnight Saturday and I weighed myself again evening of Sunday. I lost like 3-4 pounds!!! I probably lost more today, I’m not sure since I haven’t weighed myself. Is it normal to lose weight so fast after vacation? On the cruise, we would eat like 4 times a day with at least 2 plates of food each time (7 day trip), also lots of drinking, not alcohol but juices and water and all thatl. And now that I’m back, I barely even eat 3 full meals. Could this be the reason?

Maybe because you went from eating so much to eating so little? Maybe some of the weigh you put on was water weight.