Vitamin D3 gives me horrible mental symptoms, what do i do?

I'm very deficient in vitamin D; I think I was 12 nmol/L when I went to get my blood tested. I have ever since tried supplementing with D3 2000 IU (calcifediol). But ever since I started taking this, I have had really bad anhedonia, trouble sleeping, and just overall feeling very depressed. First I thought it was the magnesium glycinate causing these symptoms, so I ditched that, but the symptoms still appear with just the vitamin D.

So to be absolutely sure it's the vitamin D, I tried taking 4x different interval breaks with the vitamin D. I would wait 4-6 days, and notice all the symptoms I mentioned above get much better, but as soon as I take the vitamin D again, all symptoms appear within hours of taking it.

So my question is, what the fuck can I do? A vitamin D sunlamp is extremely expensive; it's December, and there won't be sunlight here for many months (Scandinavia). I probably can't get enough from food alone, as I already struggle with eating. I hate having to take this vitamin D pill to boost some number when taking it just makes me feel extremely horrible and depressed. It literally feels like being forced to take a poison every day that you just know will make you feel far worse. Any advice would be helpful.