It is not necessary to go to a cardiologist for high B/P or high cholesterol. Internal medicine doctors are also trained specifically on managing these issues. I myself have never heard of a B/P of 500/400. I [removed] thought that a blood pressure of that magnitude was incompatible with life.
Your B/P should not be higher than 140/90 in a resting state. Recommended total cholesterol level should be below 200 but a lot depends on your HDL and LDL cholesterol levels as well. Hope this helps!