Water retention while fasting! Puffy and nasty!

Hello all fellow health-seekers - thank you kindly for taking the time to read my post. I would really appreciate advice. I'm back fasting lol.

I am on day 3 of my second 30 day fast and have done lots of shorter fasts.

My first thirty day fast I entered very lean underweight bmi (5'6" and 113lbs), and had really been tapering down my eating having just a few mouthfuls of fresh fruit and veg for many days prior.
By day 29.5 I broke it due to having deathly low weight. That was oct 31st last yr... All my muscle waisted to skin and bone and I was severely protein/b12/folate/iron/everything deficient.

I vowed to fast again, so although having a terrible refeeding struggle I did lots of weights and excercise to get to a strong muscular 127lbs, with a body fat % of 19... Mediocre compared to most, but good for fasting.

My issue is this.... During my re-feed and bulk in preparation for my fast I have experienced sever water retention issues, to the extent that I swell up everywhere - hands, ankles, feet, face, lips, eyes, and gut. I look very awful, like I have been bashed and any definition I have disappears. It happens like every 10 days or so... I'm not sure what the trigger is... Possible after a long 9km run, or long weight set, or eating something that doesn't agree with me... But here is the problem; I had about 2 weeks of academic work just prior to my fast that I needed to smash over before I fasted. It took a nightmare stessfull week where I ate abnormally more, and probably, slightly more indulgent than I'm used to. I swelled up to 132lbs... Not overweight but heavier than I've been. So I had a week to get myself into shape for my fast. I ran 9km every other day and lifted heavy big reps until after 2 days I was suddenly 121lbs.... I suspected I had shifted a huge amount of water weight - possibly aided by my eating large amounts of watermelon...I continued my excercise and threw in one more huge work out and massive run, but otherwise keeping to 4.5km and medium reps/weight, eating moderately.

But it suddenly rushed back! All of it! (Could it have been my muscles drawing in water to repair?) So I entered my fast at around 129lbs but mainly water from all my swelling. Day 3 and the water isn't going!
I drink about 2L day... Usual. But my body is just hanging on to water!!! Why? And isn't this going to effect my fast detox abilities?

I'm already feeling like this fast is more taxing than last fast: I think primarily because of higher weight and water retention. Walking around is already tiring and I'm already lazy and lathargic, where as last time I was working on the car, the truck, walking a few km every day, here there and everywhere... My partner suggest to recalibrate and then re-enter the fast... But I'm stubburnly hoping this fast WILL BE the recalibration I'm after...

Can anyone shed some light? I will wait for answers while I sit here, swollen, puffy like I've eaten five course meals - even though I've not eaten in 3 days...

Much appreciated