Bub is almost 8 weeks now. Been breastfed since birth until about 6 weeks then I’ve started giving her formula mix due to low milk supply compared to her increased in appetite 😓

So I started off with Karicare plus a2 protein and bub had no problem with it and she enjoyed every feed. Then I’ve switched to Amptamil Essensis 1 cause I couldn’t find the initial Karicare formula everywhere and I was desperate. Read reviews online so I chose Amptamil at the end. Bub did not refuse it at the start but she started to get constipated from it as she would scream everytime when she pooped. And lots of spit ups and vomiting on this one. So I’ve changed to Oli6 goat milk which apparently it is more gently on bub’s tummy but this has been a nightmare. She would cry after every feed. Scream from pain in the middle of her sleep. Lots of spit ups and forceful vomiting. Doesn’t seem like she enjoyed her feed and doesn’t keep her full for long (or could be from the spit ups 😢). It is painful to watch her not enjoying her feed and getting less peaceful sleep due to vomiting / upsetting stomach/ excessive gas. I am wondering if I should change her back on to Karicare plus cause apparently changing formulas too often upsets baby’s stomach which I’m tryna avoid 😖 or is it just a matter of time that she is adjusting to the new formula? Please advise 😭😭🙏🏻desperate new mamma here heart broken watching baby screaming and crying over every feed 😭