HELP! Huge calorie deficits and lost nothing

Recently I accidentally gained 1-2 lbs after my grandpas funeral and I can't seem to lose them!!!!!! I've been making calorie deficits, huge ones! Today was the last day of this workout thingy for 1 week, Been doing like 1-2 hours of cardio everyday this week + eating like 1500-1800 calories a day.. but guess what.. nothing.. I weighed myself this morning and I gained 300 grams more.. Should I let my body catch up or the only thing I lost is time not weight?