I have had some issues like this. I have had OALD and OS. Sometimes when LO was smaller, he would pull off and cry because he needed to burp? Do you give gas drops on a regular basis? This helped with my LO, and I did it at every feed. He spits up a little off and on all the time and is almost 7 months. Even with OALD somewhat under control they can swallow a lot of air. Also I think my LO is teething, and this has made it worse, sometimes I rub his gums, then try nursing him. Sometimes it helps. Sometimes when he was smaller, I could hear stuff backing up into his throat, and he would gag like he was going to throw up. I think that was effects of OALD, even when I had it more under control. It can seem a lot like reflux. This got better the older he became.
One MAJOR thing that happened with us was that lo wanted to comfort nurse and couldn't, because he would be drowned with milk. He would cry and cry, nurse and cry. I finally found a paci he liked, and helped tremoundously! (MAM) Is little one gaining well? How does LO handle the bottle, you said other caretaker was having issues feeding also?