This link provides helpful information about food sources of potassium Potassium | Linus Pauling Institute | Oregon State University.

I meet the potassium RDA from the fresh fruit and vegetables that I eat.

Medication for hypertension is complicated, Current evidence suggests that beta-blockers are not recommended as first line treatment Beta-blockers for hypertension | Cochrane. Others may be better - I am on a calcium channel-blocker which works well for me.

Life-style choices, in my case regular exercise and stopping drinking and smoking, have also helped me.