Projectile vomit after formula switch

My son is 3 months old and he was on Similac Isomil since he was about a month old. He had very bad reflux before we made the switch to the Isomil. We tried Similac Sensitive, Gerber Soothe (purple can) and the Isomil.

Well, yesterday I switched him back to Gerber Sooth from Similac Isomil. He had his first bottle of it around 6:45 PM and fell asleep at my sisters house. He drank about 2 ounces. He wailed in the car ride home which is normal and nothing I could really do. We got home around 9:30 and he fell back asleep in his car seat so I put him into bed. He woke up around 12:30 just an hour ago and I made him a 4 ounce bottle and he took about 2 ounces and PROJECTILE VOMITED EVERYTHING. I mean it just kept going and going and he was gasping for air it scared the shit out of me. Now, it’s 1:30 in the morning, he just fell back asleep. He refused the bottle.. would spit out the formula and I didn’t want to try to get him to eat because I didn’t want him to throw up again. What do I do? Do I switch him back to the Isomil or keep trying with the Gerber Soothe? PLEASE HELP😞