I don't agree with mammainlove about the diet. DS2 was EBF, and I had a special diet to follow so as not to increase his reflux. I didn't eat/drink dairy, citrus fruit, tomatoes, poultry/eggs, chocolate and coffee. It didn't make him better, but if I indulged in a Latte, it made him very sick.
My DS had severe projectile vomit so violent , vomit would come through nose and mouth at the same time, apnea, chest and ear infections caused by his vomit entering in the lungs/ears, and Lanzoprazole , which is similar to omeprazole, aided a lot. We started with ranitidine but it was soon clear it wasn't enough.
I had a non-stop crying baby for 8 months.
The OP's DS now associate food with pain and quitting omeprazole would only cause him even more burns in his esophagus . But I would ask about cutting the ranitidine. It tastes so vile, I understand your DS rejecting anything that looks like it.
Did they never offer you lanzoprazole? The success rate is higher (more than double Lansoprazole vs. omeprazole.
Weaning to solid worsened things for us. He would chock on the texture and have horrible acid poos, that smelled so bad I had to change the whole bed more than twice per day, not because the sheets were soiled but for the pungent smell. What worked for us, was pear compote. Cook a pear in tiny pieces and cook it in half a glass of water then mix together.
The problem with NG tube is that it may be very difficult to go back to feeding by mouth. On the special children's heath or special needs boards you'll receive better advice. Maybe ask for your thread to be moved to Health.
I strongly recommend you post on the dedicated reflux website. It is such a relief to speak to persons who understand the hell you're living.