Probiotics?

So I think my little guy has reflux. He spits up after every feeding even though I burp him, sit him up, etc. He whines and grunts and cries all night long. I can feel the gas bubbles in his tummy. He eats every hour and I think its because the milk feels good in his throat and as soon as hes done he is fussy again. I've been doing a lot of research on probiotics and I want to try them but theyre expensive. But if they work I'm willing to pay anything! Does anyone swear by them? I was looking at Gerber Soothe or Culturelle. Or should I skip that route and go straight to his pedi for zantac? (he's 5 weeks old).

Also, I've tried gas drops and gripe water and they don't help. Or they only help temporarily.