Newborn milk allergy?

I have an about to be 2 month old baby she’s been on regular formula she started off on similac 360 and now she’s on enfamil infant neuropro it’s been a week since she’s been on it and with both formulas she always wheezes a bit when drinking it but it seems to be getting lesser and lesser and since I’ve switched to neuropro she’s had diarrhea twice and has been extra fussy since I’ve started that formula and she never was a fussy baby I wanna know if I should try sensitive baby formula? And do I have to ask her doctor before switching her to sensitive since it’s a special type of formula or can I try it for a few days and see how she does it’s Memorial Day so her docs closed but I don’t want her to be in pain :(