Reflux VS dairy allergy

I’m feeling so discouraged. I cannot figure out why my 3 month old is having tummy troubles. He spits up sooo much. Like could fill a cup.. right after he eats and for up to an hour afterwards. When he spits up it doesn’t seem to bother him but every once and a while he’ll be fussy beforehand. My dr. Said it’s nothing to worry about and if it’s not “shooting across the room” than it’s normal. But I’m not happy with that answer. The amount isn’t normal. He didn’t have any signs of a dairy allergy but I decided to see if me cutting out dairy would help. It’s been about a week so not long enough to see results but we’ll see. His poop looks normal but he tends to be gassy.. farts a LOT and it makes him cry when he can’t get it out. I do all of the reflux precautions.. I don’t let him have my fast letdown, I burp him, hold him upright afterwards..doesn’t seem to help. What else can I do? Are there for SURE signs of a dairy allergy?