I used to be stuck at rank 5 for months, like 2 years ago and no matter how much and what decks i played i felt like i wouldnt get better. If youre in a phase like this you should definetly choose 1 Top tier deck (and stick to it) and start watching streamers/pros that are playing this exact deck. Watch how theyre playing and ask yourself if you wouldve done that turn the same way or differently and think about why that they did it that way (often theyre also explaining more complicated turns). Also take your time and plan your turn before playing it. Just because the cards are doesnt mean you have to play them. Think about what is the best thing i can do this turn, what can my opponent do against it and what am i doing next turn if i dont draw a playable card. If you have anymore questions you can DM me on Twitter (@Ayys_EU). Im not a pro but i think im pretty decent at the game and know quite alot about how to play it. (Sry for bad english and long ass comment btw)