My 7 week old excessively spits up / vomits at almost every feeding. It doesn’t matter if it’s breastmilk or formula, breast or bottle. I’ve tried multiple bottles, nipples and formula. I’ve even tried adding cereal to thicken. I burp him frequently and keep him upright during and after feedings. He’s already on Zantac twice a day but I’m worried about proper weight gain and development since he spits up so much... he was already little at birth (under 6lbs). Any tips or tricks?

He frequently cries during and after feedings (tummy discomfort) :( This FTM doesn’t know what to do to make him feel better.