Attn: Joe De Livera - possible silent reflux and gassy?

I am a little concerned for my 9 week old son, who seems to possibly have silent reflux and is very gassy baby. He has always been very hard feeder - he had tongue tie which got snipped but has still had issues with feeding.
At the beginning was exclusively breastfeeding and he would finish feeding, be in pain, arch back and turn bright red and couldn’t lay flat on his back and I would notice he had a bit of spit up that would come to his mouth and he would swallow - he would then want to feed more and the same process which felt like he was comfort feeding.
At the time I thought he wasn’t getting full from breastfeeding then started pumping and now currently doing formula and breastfeeding but still same issues - he’s a happy baby but having so much issues with feeding - at the moment and last few weeks he seems to not want to feed and would cry when comes on the breast or given a bottle.
He has lots of hiccups, congested nose, he squirms after feeding and almost smashed his head from the pain on our chest - his diapers are green and seem like acidic and explosive.

At the moment he’s sleep has become worse and he wakes up and I notice he’s had a spit up and had been squirming.

Please advice what I can give to help support my son?