Please help! Formula question!!

My LO is currently 8 weeks and she started out on Similac pro advance, then to advance a week or two later due to wic. She was extremely fussy, gassy and would scream a lot and hold her breath. The dr switched her to Similac alimentum and at first she seemed a bit better except it was harder to get her to eat. She would eat 2 oz instead of 4. But all of her symptoms are back and she recently developed a rash and her poop has been light green/ yellow almost goldish and maybe the littlest bit mucousy. She was on the alimentum powder for maybe almost 3 weeks before I started to give her the rtf last week, thinking maybe she has a sensitivity to corn. The first night, she was amazing and didn’t scream and cry once but the symptoms have once again returned. The only pro is that she eats 4-5 oz again. So I call her dr and they had me bring her in yesterday. All he said was to put cereal in her bottles for acid reflux and gave me Nutramigen & gentlease to try if she doesn’t get better. And said her rash is just acne not an allergic reaction like I thought. She’s been on the cereal for a little over 24 hours now and nothing has changed. I think she does have silent reflux because she doesn’t spit up all that much but gags and makes grossed out faces and sometimes won’t drink her milk. But I deep down feel like it’s more than just reflux. She’ll scream and scream for an hour or more and holds her breath still. Is it even worth it to try the nutramigen since they’re similar? Or would it be worth to mention to dr about an amino acid based formula? He didn’t give me much hope saying alimentum is the best but it doesn’t work for us at all. I just don’t know what to do anymore and it’s breaking my heart to see her in so much pain.