HELP!!

I have a 6 week old who projectile vomited at least 1 time a day from about a week old on. she gasps and wheezes and arches her back and is often fussy and pulling off repeatedly during feedings. She wasn’t napping or sleeping well at night. Around 3 weeks we tried maalox before feedings and sleeping on tummy(i know, bad) and she was a different baby. 3 naps a day, 4 or 5 hours of straight sleep at night, liked to lay down and kick around, not screaming all the time. After 10 days of bliss her symptoms returned, but much worse. She was awake for 10 hours straight and screamed for 3 straight. vomiting multiple feedings a day, and of course spitting up regularly. no more naps or only 10 minutes while being held, waking herself up at night making horrible gasping, grunting, and wheezing noises, sounds like she is choking, lots of gas, and also started pooping more frequently(7 or 8 times) after having slowed to 2 or 3 a day. My girl was so sweet when she felt well and she is going back to being miserable again! we are trying zantac morning and night and maalox at 4 feedings, but so far no better. She vomited both breastfeedings today, but did keep down 2 feedings of breastmilk given by bottle. I have not been eating anything spicy or any fresh veggies and only having a dairy product once a day or every few days. WHAT TO DO????