Just wondering how you would say "I'm so confused" or just, "I'm confused", for context it (if needed) would be for deciding something, if someone couldn't decide what they wanted, what would be the Japanese equivalent of "I'm so confused" or "I don't know, in so confused!" ("What is going on!?" Would also be helpful! Which I think is something along the line of 何ですか？)
I would say, that when presented with a difficult choice and cannot decide, many people would use some form of 迷う (迷っている、迷う、迷うなぁ, etc.）. While the more common definition is 'to be lost', another of it's definitions is to waver, hesitate, vacillate.
「どれにしようか迷っている。」I can't decide which to choose.
Another option would be 悩む: to be anxious, unsure, distressed.
「決められなくて悩む」I'm unsure and can't decide.
These expressions can be shortened to utterances of 「迷う」and 「悩む」to express uncertainty.