(((hugs))) Emma
I have been here too. Went to GP when DS was 4months, as reflux was continuing & he had eczema & facial rashes. At the time he said it could be milk intolerance but that they didnt usually do anything except just wait for LO's to grow out of it. I listened to others who said DS was just a fussy baby for several months, then finally plucked up the courage to go back to the GP as since starting solids his reflux & rashes have just gotten worse. He was reasonably understanding, but I had huge difficulty actually getting a prescription, as he is clearly not well informed about reflux/intolerances and wanted me to put DS on Soy milk. I said no so he asked me to see the HV & for them to decide which formula he should prescribe me. HV was clueless too, told me to ask a pharmacist, who said DS just had wind & I should burp him better (the cheek!!!). I think a lot of health professionals are just ignorant about intolerance issues & dismiss it as wind, fussy baby etc, but they are not the ones living with a baby who is suffering.
I finally got hypoallergenic milk - Aptamil Pepti - as I went back to the GP & specifically asked for that brand. No-one has checked it is actually suitable for him at all, but at least its enabled us to start a dairy free trial.
His skin rashes have all but gone, his eczema & cradle cap is clearing & he's still a bit sick but not as much. We ran out of the formula & had to use the old stuff & it all flared up again. So its proven to me that he's dairy intolerant.
I guess all I am saying is stick to your guns. You know your LO better than anyone else, if you feel there is something wrong, go back to your GP again, or like pp's have said, ask to see another GP or for a referral to a paediatrician. I have actually done this too, even though I have the HA formula already, just to make sure DS is given reflux meds if needed & that we are giving the right diet to ensure he gets his calcium requirements.
As for cooking AK recipes - I use her books too - & use 'Pure' sunflower spread - its dairy free & you can get it in Morrisons & I'd guess some other larger supermarkets. We've also got some 'Oatly' oat milk - its in supermarket with the long life milk - (Tesco sell it). Not used it in cooking yet but hear its fine. I make up extra formula to put on his cereal & just add some fruit puree to sweeten it up as its quite bitter.
HTH.xx