Spit up is making me CRAZY

My little fella is just shy of 12 weeks. He sleeps 5 hour stretches at night, naps like a champion, smiles and babbles at me constantly, and has really nailed the pooping/farting thing.

And I’m still losing it because he spits up constantly! I know they say “it’s not as much as you think, it just looks that way” but it 100% is tablespoons at a time, 6-8 times after almost every feed. I would say on average he’s spitting up almost 2 ounces out of every meal - except overnight. He will nurse and go back to sleep (on his back) without losing a drop - until he decides it’s time to wake up in the morning and then he’ll start spitting up his most recent overnight feed, even if it was hours prior.

We’ve tried holding him upright after meals, feeding him upright as possible, trying to keep him calm and not too excited after eating. Our doctor prescribed omeprazole which changed absolutely nothing - I’ve read that omeprazole doesn’t reduce spit up, just the acidity of it? If you have any clarification on that please let me know, our doctor is useless when it comes to providing information.

He seems to be gaining weight well, he’s never once cried after spitting up, his poo is normal. His spit up is only ever straight liquid milk or curdled chunks, no worrisome colours. It mostly just falls out of his mouth with little to no force behind it. Occasionally he’ll cough on his spit up but it’s literally 2-3 baby coughs and then he’s done (this was the only aspect our doctor seemed concerned about when we saw her, and the reason she prescribed the omeprazole). I also gave up dairy completely for 3 1/2 weeks.

Am I just doomed to have a soggy baby until his esophageal sphincter sorts itself out? Is the spitting up going to harm him in the longterm if we just let it keep happening? I’d prefer not to have him on omeprazole anymore if it’s not doing anything meaningful.

If you had a similar situation and found a solution, I’d love to hear it. Thank you!

EDIT: I BF, we’ve also tried giving him bottles of pumped milk so that we can control the amount & speed at which he eats. No change unfortunately.