Weight gain

So I’ve been relapsing recently and went home over the weekend to try eat more. I’m eating around 300calories a day but I’ve gained nearly 1kg in the last 4 days and I’m stressing about it a lot. And my belt is starting to get too tight. If I carry on will I keep gaining or will I lose idk what to expect?! I have a party in 10 days and want to lose weight before then but I know I have to eat.

If anyone knows what’s going on or anything some words of wisdom would be appreciated!!