Hydroxycobalamin injections EOD - nausea, dizziness

I've been taking 1000 mcg hydroxycobalamin injections every other day for almost two months. Recently, I've started feeling nauseous, and during the injections, I experience anxiety, dizziness, and a feeling of intoxication. The last injection was terrible. After 10 minutes, I was overcome by a cloud; I couldn't think straight, thinking I was about to pass out. What's happening to me? This has never happened before.

I'm doing all this to get rid of the brain fog I've been experiencing for a long time, but after the injections, my cognitive function has only worsened and the brain fog has gotten worse.

Cofactors:

- Methylfolate - 4 mg daily

- Thorne Essential B Complex - 1 tablet daily

- Magnesium Glycinate - 400 mg

- Potassium 300 mg, Calcium 185 mg

- Vitamin D - 2000 IU daily

- Seeking Health Trace Minerals Complex - every 3 days - for some reason, my symptoms get worse after taking it.

After I started having skin problems (it became dry), I started taking it for a week now:

- Vitamin A, 3000 mcg 10,000 IU - daily

- Vitamin E, 67 mg (100 IU) - daily

- Omega-3 Fish Oil, 500 mg - daily

I don't take iron because my iron test result before the injections was 220 mcg/dL.