Took one month to lose 2 kg yet somehow regained it in 5 days ! Why !? How ?

I was seadily losing weight, cut desserts out of my life. Divided breakfast by 2 in quantity.

Also I first fill my plates with vegetables then add things like fries with the little leftover space I have.

It was working well but récent we moved out, we ate at restaurants a few times cause no working kitchen. I tried eating as little as possible. Plus I just move hundreds of kilos of fournitures and we're still no done, sore muscles everyday... it should have been plenty of exercise. Yet in those 5 days I gained 2 kg ;-;.

I'm kind of losing hope, I was aiming at consistently losing 2 kg/month but now what's the point ? When something seems to work it suddenly stops working. I'm so tired all the time, should I eat even less ?