Rancid taste and mucus problems on water fast.

Hi everybody!
This is my first post and I would really appreciate any advice.
So, a little bit of background information:
I am 21 days into a water fast. The first week was water with a squeeze of lemon and the last 2 weeks have been water only.
I started the fast to kickstart a healthier lifestyle and also to lose weight. I've been sleeping lots, plenty of rest, the usual light-headedness when I stand too quickly and slight feelings of nausea when I have a shower (I curl up in a ball for 5 minutes afterwards to alleviate it no problem) these things were all to be expected. No headaches or cramps.

My problems are as follows:

1. In the last 4 days I have had the most God-awful taste in my mouth, I'm brushing my teeth several times a day and rinsing with mouthwash but the relief is short lived. I have a very light white coating on my tongue but really nothing extreme. What is causing the taste? I've read suggestions of too much bile (I had my gallbladder removed, would this have an impact?) or an electrolyte imbalance, ketosis, kidney issues, or even too many toxins, but this has only started happening around day 17 of my fast. It's making me feel physically sick. What can I do to remedy it? It doesn't taste metallic.

2. This is particularly disgusting so I apologise in advance.
I seem to be producing a lot more mucus/snot and it's running down the back of my throat. This too has only started in the last 4 days. I've been blowing my nose but it's not stopping the mucus running down the back of my throat. It is definitely originating from the nasal area (possibly sinuses?) I do not have the mechanism that allows people to hack up mucus/phlegm so I can't do anything except let it trickle down into my stomach (i warned you this would be graphic) it really unsettles my stomach and again is making me nauseated. I have to try to sleep when it gets bad or I would surely vomit.

3. I have not lost any weight in several days, I still have a lot of weight to lose so I know it is not because my body is at its ideal weight.

4. I have still been having the odd bowel movement. Every 3/4 days. They are very liquidy and the last one was particularly pungent, more so than any of the others have been, it took me by surprise because the others have been relatively odour free. Does anyone have any theories on why that could be?

I am planning on breaking my fast tomorrow with lemon water and freshly squeezed juice, diluted. Then perhaps some Watermelon in the evening or the following morning depending on how I'm feeling. Tweet