I have a hiatal hernia. if i don't stick to a diet since i have bad acid reflux what will happen? will i have to see my gi every year for a check up?

Follow diet: Don't ignore the symptoms that are trying to tell you something. You may suffer long term damage to the lower esophagus. Your diet is important as is maintaining a good body weight. If your symptoms are not adequately you might controlled with meds, you might be a candidate for a surgical procedure that usually works well. And yes, ignore advice and you will get to know your GI doc well.

Check up: You should check up yearly. Your doctor will monitor your progress. If you have good control then perhaps no changes will be needed. As you age having a doctor who knows you well and can offer good advice is priceless. They can save you an operation or recommend an operation and save your life. That is what they try to do every day.