Well firstly, I'm not a fan of extreme diets; I believe the body will try to fight that ...
Secondly, there are other things that can affect your weight from day to day: the most obvious is water retension which is common to us all, often caused by salts from our daily meals. Then there is your menses: that can cause bloating and more water retension. If you are on your feet and legs a lot; they can swell and hold water too.
We must understand the process of weight-control; there will be days you lose, days you gain, and days you maintain. Personally, I believe weighing daily is just setting yourself up for upsets. I wouldn't weigh any more than once a week at the very most.
One of my doctors had me weighing every 3 weeks. I asked him why and he said that would account for menses & salt-related water retension; and usually you are more likely to see a true loss by that time. He was correct; I went every 3 weeks and lost every time.
Now there is a possibility you may have some thyroid issues; but it depends on whether you have the symptoms or not -- only your doctor or naturopath could tell you that. I'm not a doctor; just a fellow soujourner ...
I can only give you my best guess; and I hate to see you driving yourself crazy over these fluctuations. Yes, I have had them myself becuz my body retains water a lot for the above mentioned reasons. I have cut my salt intake down drastically becuz of this.
I hope you get some answers soon; but in the meanwhile, I wouldn't weigh quite so often ...