Tell me all about switching from breast milk to formula.

My almost 6 month old has been on breast milk only since birth. Around 12 weeks I went dairy free due to mucus and colic and she improved. I challenged her twice around 4 months and 5 months with frozen breast milk and the colic came back with a vengeance😞 we just started solids and in about 2 weeks I’m going to challenge one more time and if she fails i plan to switching her to hypoallergenic formula. I just can’t do this diet any longer. Hopefully she will tolerate the dairy again but I don’t feel too confident. I’m super nervous about how she’ll do on formula… I’ve heard it’s stinky and tastes bad. I really don’t want her to reject it. Anyone have any experiences with this?