Switching formula?

My baby is 10 weeks old on Thursday, she was on aptamil advanced milk since birth and we had problems with her bringing some milk up so we switched quickly to aptamil reflux milk which made her very constipated where she was straining and crying constantly. I got prescribed lactulose from the dr which to me is not a long term solution. Now she’s older and more developed I’ve recently moved her back to aptamil advanced as it could have just been me being paranoid moving her to a reflux milk so quickly. However, we’ve been on aptamil advanced for 2 days and she is crying after the odd bottle and does bring up some milk but other times doesn’t, some bottles she cries some bottles she doesn’t. I don’t know what to do for the best? Is it just her being a normal baby? For example tonight she’s screaming after the bottle. Has anyone moved from Aptamil advanced to a different milk and it has helped their baby? Thank you from a very tired and emotional mummy!