getting to an extreme demon

my current hardest is B which took 1.1k attempts, i play the game around 1 or 2 hours a day and im planning for my next completion to be nine circles as a hard demon, then something like windy landscapes as an insane demon, and bloodbath, acu, or cataclysm as an extreme after all that. so according to that how long do you guys think it will take me to beat my first extreme demon because im really getting de-motivated since im barely improving at the game