Sorry you’re going through such a tough time with sleep. As PP have said, it sounds like the 4 month sleep regression. Essentially his sleep cycles are maturing, so he is waking in between each cycle. This is very normal, and we all wake briefly between each cycle of sleep. It is an evolutionary measure to keep us safe apparently - we wake, check our surroundings, back to sleep.
The issue is that DS isn’t falling to sleep where you want him to stay asleep - he is falling asleep on the breast, then being moved. So when he wakes briefly between cycles, he realises he isn’t where he started, wakes fully, and needs settling.
Your first option to get through this is to bedshare safely, so that DS can feed to sleep, and easily latch on again when needed.
Your other option is to try and move away from feeding to sleep, and try and find other ways of settling him, eventually moving to him self settling. You could try patting him, rubbing him, rocking him etc. This will very likely involve some crying, as he is used to feeding to sleep. You do not have to leave him alone at any point though- just try other ways of soothing him.
If you are able to eventually settle him with patting / rocking etc, this is easier to wean from than feeding to sleep - slower pats, less rocking etc. It will take time though. (But also means someone else can settle him).
Have you tried a dummy? If he finds sucking comforting, this may well help him settle.