id take out ragnaros, ysera, faceless manipulator and nourish.
Probably would be wise to remove 1 of Your mark of The Wild since you most likely will have the bigger creatures anyways and your just opening yourself up to a silence taking out multiple cards of yours on top of you have so many taunts as it is already.
While your deck is fun to play, I have one like it as well where I just throw in every legend I have and it does its job well. But the higher in rank you go the more streamlined and consistent your deck needs to be, this is why you are hitting a wall, because your deck has glaring holes that make it weak to a variety of decks that will consistently produce threats every turn.
A ysera is really only useful against a priest and if you can double innervate it out early, and also useful in the mirror match because opposing druids have no real option to take out 12 hp. Against every other deck its a waste of a turn, Hunter will mark it or deadly shot it, mage will sheep it, shaman will hex it, zoo and aggro pally will kill you before you play it and rogue will combo out before you get it as well. So a card slot dedicated to helping you against 2 decks in the meta that are not the most popular ones to play by any means, on top of that you actually have to draw it and it being just one chances are you wont when it will produce the best effect.
Ragnaros is complete RNG, you have no control over it. It could just as easily hit a Harvest golem and be a complete waste of your turn as it could hit something you want. On top of that its the only creature you have over 6 attack so you have created a situation where every opponent playing BGH will just sit waiting for you to drop that one minion you have, chances are Rag will be BGH the second you play it. wasting your turn.
Nourish has its use, and its not in control. If your looking for draw, throw in ancient of lores and azure drakes. If your looking for crystals, you already have innervates and wild growths. Mid game, turns 3-6 are control druids most important turns, you need to establish board control and wipe out your opponents threats. Wasting a entire turn on something that does nothing to achieve either of those goals is a death sentence. Nourish is best used in an aggro based Druid deck.
If your looking for your next craft, IMO its def TBK, you will love this card in mirror matches and many decks now run Senjin as a answer to zoo, you will get value out of that card more often then you wont.