Need honest opinion

Back story: I think my son has a dairy allergy..he pooped blood when he was 2 months old so I cut it out of my diet..I look at anything that has dairy in it, which is like everything I would eat so I’ve completely changed it around. My son also has reflux..

So like a week ago i tried dairy again(his doctor said to try it to see what happens)

Well day 2 of trying dairy again my son was in his bouncer and started having really bad reflux where it kept coming up and he kept swallowing it right back down which like stopped him from breathing.

Now I’m not sure if it was from the dairy and effecting the reflux cuz they say for some people reflux gets worse when eating dairy or it was simply just the fact that my son now sits completely up and leans forward in his bouncer so maybe he’s putting a lot of pressure and leaning against his belly making the reflux come up? Im saying this because it’s happened before in my arms recently of I accidentally have my hand against his belly in the wrong way.

I’m not sure. I need opinions.