Sorry to hear you are having a bad time.
6wo ds had his TT cut at less than a week old - the doctor (Paed surgeon at St George's, so he has seen a few!) said that in his experience it is not the cut that bothers them, but being held down. Indeed, DS was swaddled tightly, whilst one doctor held his head down and the surgeon aimed the scissors and snipped. DS was furious but the second he was handed back to me, fell straight back to sleep. So if you do go down this route, please don't worry about the op!
However, from what you have said, it sounds more like silent reflux (my other 2 boys had this - one severely). I think it starts to become apparent around now and for me, peaked at 3-4 months. I found that my reflux boys (!) would go rigid whilst feeding and scream through a feed. I could only settle them with a dummy. Feeds took forever - dummy, feed, dummy, feed and so on. They were impossible to wind and DS2 used to projectile vomit at least once a day. He also always smelled 'acidy'. He slept like a log at night though, but only ever settled on is tummy.
Interesting what you say about reflux and TT link. My 2 older boys are TT and both were a nightmare to wean - they would NOT touch purees so had to BLW. Transpires that TT babies find it difficult to move the slop to the back of their mouths. However, they both eat like a dream and I am TT and had no adverse effects!