Which supplements can cause serious dehydration even you drink enough?

I have very a serious problem with dehydration since a year or longer, and it got dramatically worse over the past months. I noticed that my skin became more and more dried out, and then I got an inflammation in my right eye, which was around 1 year ago. I went to the eye doctor, and he told me it was mostly caused by too dry eyes, and told me I should use artificial eye drops. Which I started to take, but they literally did nothing. Eyes kept very itchy and dry.

I then noticed, some weeks later, that my entire mouth and lips got more dry when I woke up. It got so bad to the point, that my mouth was paper dry when I woke up. This never happened before, that it was that dry.

And a few days ago, I had an attack, that I got vertigo, had to vomit, and went to the nose/ear/throat doctor today, they did some tests, and said I mostly have crystals in my ears causing this and told me I have to do some exercises which helps to bring out the crystals out of the vestibular organ in the ear. They didnt tell me which ear it was though and I have to look into these exercises the next days. I am feeling just terrible right now, getting strong vertigo when I move from sitting to standing or laying position and feel really sick.

I just googled about the crystals in the ear, and it mostly said, just older people and women got these, mostly over the age of 50, but one site also said dehydration could cause it. And that triggered some alarms because of all my other dehydration symptoms. I am just 38 and male.

So I got the idea, that some of my supplements might cause the dehydration.

Here is a list of things I mostly take daily, since a year or so:

- high dose vitamin C around 1-2g

- Vitamin D3 5k + 100mcg K2

- magnesium glycinate (total of 300mg of magnesium)

- potassium citrate around 500mg of potassium

- agmatine sulfate 500 to 1000mg

- R-ALA 300mg

- B1 as Allithiamine 50mg (started this though just around 2 months ago)

- omega 3 as fish oil around 500mg DHA+ 500mg EPA

- switching between copper 3-6mg copper and then the other day zinc 25mg (take a pause though sometimes for the zinc for several days)

- Molybdenum 100mcg

- Boron 3mg

- methylcobalamin 2-5mg as drops

- creatine 3g

- glycine 5g

- TMG / betaine 500mg

I also take rarely an a-z vitamin supplement, just maybe once per week though not daily. Also mostly once per week high dose niacin acid around 1g for skin flush effect. Also I sometimes take 500mg NAC but also rarely.

I also started to take these just since 2 weeks daily:

- folic acid as metyhlfolat 1.5g

- Pantothenic acid 1.5g (wanted to see if it helps for acne and dry skin)

Could the high Vitamin C cause the dehydration? I remember I read somewhere before Vit C could cause it, but I cant find the link anymore.

Any supplements which might help to boost hydration again?