My daughter used to projectile vomit constantly. We put her in her seat to sleep until she was almost 4 months old. She did much better in an upright position. I nursed for a while and cut out all dairy and any vegetables that might cause gas. Yes, I was hungry a lot! We ended up switching to Nutramigen which is a hypoallergenic formula. She did wonderfully on that. It made a world of difference for us. Good luck.