Baby throws up from formula?

My baby was ebf for 6 months. But we've had to make a transition to formula because I'm pregnant and im barely producing any milk. I have tried Enfamil and Similac for sensitive tummies. But he literally projectile vomits about an hour after he eats it and breaks out in a rash. I'm on the verge of tears I don't know what to do. He's starving but i cant keep giving him formula if he keeps vomiting. Has anyone experienced this. I'm going to call the doctor in the morning.

*update* thanks everyone! I tried a milk free and lactose free formula and he does wonderful with it!