weight stabilisation

I am having a hard time stabilizing my weight. I am clueless as to why but my weight fluxes so rapidly and unpredictably. No exageration. Last week I weighed in. Last weekEND I weighed in more than 5 pounds less. Today, yet another 5 pounds less and if it follows it s usual pattern I will likely be back at the starting point by s ome time next week. All I can figure Is Water weight, but I eat the same allthe time (admittedly I could deff lower my salt intake) why would it flux by so much so fast? I know I need to figure this out because how the heck can I lose weight when I can't even control it, and I wanna do so pre-op.

Could it be hormonal??? (Sorry gents but small TMI ahead) I have severe PCOS... like 2x worse than it was 2 years ago and it was bad then. I haven't had a natural AF in well over a year, I induced one last June, and recently tried to do so again but only got spotting this time... no AF. If its hormonal then I am screwed because the only reset button I have is provera (to induce AF) and that's not working. This has been going on for a few months and I don't yet have ins. Coverage to talk to my doc about it, he called in the script for me as it was.

Any thought, hints, tips on what could be causing it and what I can do about it? I am desperate to get it under control so I can show my sugeon I am serious about changing but that's gonna be hard if he weighs me in one month then the next I have Gained 10-15 pounds. TIA.