Reflux/colic in 4 month old

My son is 4 months old and 14.2 lbs. To give a little history on him he was born 8 days early with a vacuum assisted delivery at 7.1 lbs. From day 3 on he has had feeding/tummy troubles. He would scream immediately after breastfeeding like he was in pain. He cried all the time even when not eating. We could never lay him down he had to sleep in our arms and he spit up a lot.. He was ultimately diagnosed with a cows milk protein allergy/ sensitivity and colic. I switched to soy formula while going on a strict no dairy diet for 3 weeks and ultimately pumping didn't keep my supply up and I stopped lactating. He began to not do well on soy so got put on a hypoallergenic formula. He did well on this for a week or 2 then began projectile vomiting and pain. He was diagnosed with reflux and put on Zantac at 2 months. He did well on this for 1 month then Reflux came back very bad. We began thickening his formula with rice cereal and he did well for 3 weeks now isn't doing well again. He is constantly irritable and fussy, only naps 2-2.5 hours total a day broken into little cat naps, is now waking up every 45 mins- 2 hours at night whereas he used to only wake up 2x, arches his back in pain or draws knees up to chest, sounds gurgly and congested all the time although lung sounds are clear, is hysterical when in infant car seat in car, has to be swaddled to calm him down, sometimes refuses bottle, grunts a lot and gets hiccups a lot. His spit up is minimal but I believe he's having silent reflux and is in pain so he's fussy and won't sleep. I need help!!!! He has happy moments but they are far and few between lately. I've tried hylands colic tabs, gas drops, and Tylenol. Also I might add we have to bounce around to get him to sleep with white noise playing, rocking no longer works.