My baby spits up a lot

So my LO is at 1month 8 days and I’ve been thru a few formulas due to his spitting up and also vomiting. He started with enfamil and then I realized he was pretty unpleasant with it. He would almost always vomit minutes later or right before I burp him. Then I tried gentleease, same issue.

I switched to similac sensitive and that seemed to help the vomitting, it wasn’t as frequent but it still happened. Also the spitting up wasn’t as much anymore.

Then I decided to try similac for spit ups and that seemed to constipate him and he still continued to spit up and vomit with that. Now I’m onto the similac advance to see how he does with it. Today is his first day on it so it’s hard to say obviously. But he spit up a bit and vomitted when I changed his nappy.

Another issue is that even after I’ve burped my LO and put him down to change his nappy if he did do a big one he would almost always vomit. And sometimes I would hold him up for longer periods and then set him down but he would still vomit a little. I’m seeing my pediatrician on Monday but would like any advice possible!