I Have Been Taking Prilosec For More Than Twenty Years.

I have been taking prilosec for more than twenty years. I have been told that Zantac 150 is a better choice. Do I stop taking the prilosec all together or do I slowly need to come off of it? I have had three endoscopies, two colonoscopies, several upper gi's and a gall bladder test all have come back normal. However without a prilosec every day, a glass of water gives me heartburn. Thank you