Hi Hann12, we had issues with reflux and a lot of what you describe makes sense. I'm certainly no expert, but this was our situation:
It started when LO was 2-3 weeks old. He would spit up after every single feed (and often in between feeds); sometimes I wondered how it was possible that he was gaining any weight at all because lots of the "spit-ups" were massive. Frequent burping and Ovol made no difference for us. I've heard from lots of people that their babies with reflux would pull off the breast screaming, but in our case he would refuse to let go even after the feed was finished (he seemed to need that tiny trickle of milk to neutralize the stomach acid). When he was lying in bed, he'd often wake up suddenly and start shrieking (often preceded by a cough or a gag). I hate that I remember it this way, but it was a terrible time. He screamed constantly and I was in tears most days because nothing besides having him on the breast (not even really sucking) would calm him down. I don't know if this is related to reflux, but my LO had many green poops in the first 6 months no matter how I changed my diet or tried to adjust his feeds.
Some things that helped us a bit were elevating the head of his bed and holding him upright after feeds (although not in a sitting position, as this put pressure on his belly). I've heard from other people that it helps to offer smaller, more frequent feeds, but he seemed so desperate to eat that we were never able to try this. He was a very different baby once we started him on Prevacid (it took about 48 hours to really make a difference) but it was still difficult as he often threw up the medication and still seemed fussier than the average baby. In the end, time was the biggest factor. At around 3-4 months, he was still spitting up constantly but he was smiling. It was more of a laundry issue than anything else. He kept spitting up frequently until he started crawling just before 7 months.
Luckily, my doctor listened to me when I told him I thought it was reflux and gave us medication right away. I know some doctors are hesitant to do so, but it made a real difference. I guess they're usually not concerned unless weight gain is an issue, but since my little guy was sucking constantly, his weight went from the 25th percentile at birth to the 75th at 3months (it has since stabilized between the 25th to 50th percentile, but he has 3 chins in all his 3month photos
). If medication hadn't been effective, we discussed some testing that might be necessary (a swallowing assessment to determine whether thickened fluids were required and some testing to make sure that his throat wasn't completely eroded from all the acid), but luckily never had to go that route.
I don't know whether reflux is your problem, but it's definitely worth considering. I hope you find some answers