Nidalee is the reason you're losing bc its a completely different play style compared to the other champs you're using to get to challenger. You get over agressive early and go for kills that you need your teams help for, so youre constantly pinging them and getting them to leave for what is most of the time a 50% chance at best of getting the kill. This causes your laners to lose their rythym and mess up their lanes trying to help you and then they start take more bad fights on their own, which causes the game to spiral out of control. Thats why theres always people saying to stop playing Nidalee on the climb. Not only that,you take that constant need to fight in your subsequent games after, causing you to throw 90/10 out the window, make bad plays, tilt, and then lose multiple games. That's exactly what happened a couple vods ago when you were on a win strak, played Nidalee, got destroyed, and then went on a huge loss streak even losing to a yumi top. Just because you can adjust your playstyle to Nidalee, doesn't mean your team can. You're playing with worse players that don' think like you do, just keep that in mind. So yeah, would be a good idea to closet Nidalee until challenger is hit.