I got headache, pale, blurred vision. Sudden loss of weight. What should I do?

Multi-symptoms. U need to consult your primary care doc. For full exam & thorough blood work to rule out medical causes.
Cns problem. This can be a sign and symptom of brain swelling from tumor or inflammation or infection or other systemic inflammation. You should see your pcp as quickly as possible. This can be life threatening problem presentation.