Pheochromocytoma. Should we do next?

I have been suffering from fast heart rate with out any cause since 5 years... Symptoms are increasing now... My heart rate is always high plus fluctuates BP... Also, winters causing stress over my body causing polyuria symptoms.. Initially doc said its may be anxiety attacks but my symptoms are not responding to medicines n always come n go In 2018 to 2019, I have a problem of heat pains, heavy headache zits, full body discomforts n heat generation... Symptoms stay for 6 to 7 months then calm for sometimes automatically Now, this time new more symptoms find polyuria, on off BP, fast heart rate, n many more.. Basic reports are fine Doctor want to test metanephrine serum n catecholamines serum to find it... What should we do next?