I Am On Irbesartin (probably Spelled Wrong) For High Blood

I am on Irbesartin (probably spelled wrong) for high blood pressure. When I first started, my blood pressure went down, but a year later, it was very high again and the doctor doubled the strength. Should I be seeing a specialist? I asked him why it would go up so much. He kind of shrugged and mentioned genetics. I'd also like to do everything I can to lower it naturally. All he mentions is to not eat fatty food etc. I am 5 ft, 5 in., weigh about 140 lbs. Never smoked or drank. Mom and her family all have heart failure. I am 61 years old.