Hair loss is a rare side effect of Prilosec. Prilosec contains omeprazole and is used for gastritis and GERD (gastroesophageal reflux). Eat small nutritious meals at frequent intervals instead of a heavy single meal. Exercise frequently and take your dinner atleast 2 hrs prior to bedtime. Also raise the head end of the bed by 2 blocks.
You can also take some antacid like Maalox and Mylanta or medications like zantac after consulting your doctor.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.