Reflux help

AZ

My baby is now 4 months old. He was initially mix fed, now only formula fed and has been on omeprazole for about 2 months for his reflux. I feel like it has not helped at all. He will still bring up milk 2-3 hours after he had his last feed. I have to keep him upright for 30 minutes after too, I just don’t know what to do. Does anybody have any advice? I’m just tired of washing sick clothes and telling everyone that picks him up to be careful how they hold him otherwise he’ll throw up.

He drinks 4-5oz every 3-4 hours and around 24-28 oz in 24 hours.