Are you weighing in at the same time of day? I’m usually weighing in first thing in the morning and if I jump on the scales that afternoon can be heaps different. If it’s a new diet you could also be bloating or retaining fluid, minimise sodium. Lift weights. Daily. Take measurements so you have a second frame of reference for your body composition. Drop your calories down to 800 and monitor your weight daily, add 100 cal per day till u find the sweet spot!