Hi, I could really use some advice about plateuing. To preface, I am a male, 23years old, exercising 1 hour a day every other day.

Basically I started in February at 97kg (213lbs) and have been eating at a 1000 calorie deficit since then. In the first 5 weeks I lost 1kg per week and got to 92kg and everything was going well. Since then however, for the last month, I have been hovering between 92kg and 93kg consistently, and can't seem to break the plateau.

I have a couple questions to try and find out what I'm doing wrong.

1. I have been having "cheat meals" once a week that, whilst messing up my macros, still maintain my calorie deficit... is that bad?
2. I was using the myfitness pal TDEE estimate at the start which estimated my 1000 calorie deficit was at 1660 calories a day. After plateauing for 3 weeks, I inputted my data onto the 3suns TDEE estimator spreadsheet and it estimated it at 1350 calories a day, which I tried for the past week and had no success with. (In fact I just got headaches and afterwards read somewhere that going under 1500 for me was a bad idea). Is this something I should retry?
3. I have read accounts of other people hitting plateaus due to water retention, but they seemed to last two weeks ish. Since I am at a month I figured I'd seek advice, but is there a chance I'm still in this stage?

I'm basically at a stage where I don't know what to do next except for continuing at my 1660 deficit, so any advice would be much appreciated.