I understand why this feels frightening, but your normal neurological assessment, eye examination and ability to function are reassuring. This pattern is much more consistent with anxiety-related symptoms, migraine/tension headache, or neck muscle strain than a brain tumour.
B12 of 219 is borderline and can contribute to tingling/fogginess;
vitamin D deficiency may add to fatigue, but neither suggests cancer.
Seek urgent care for a sudden worst headache, weakness, speech/vision loss, repeated vomiting or loss of balance.
Next Steps
Arrange an in-person examination and review your headache pattern, sleep, stress and neck. Discuss repeat
B12 and
vitamin D testing with your doctor. Book a Practo consultation if you want me to review this properly.