I dominate the early game but can't transition that lead to a victory

I am a jungler and my main is Warwick Most games I start off very strong, usually with a cs of 55ish and kda of 4-0-2 on average. My problem is that the early lead that our team gets doesn't transition to wins. I can spend the mid game helping different lanes and taking objects but I usually end up on the defensive by the late game.

As a jungler, what should my priority be in the mid to late game to make the most of my early leads? I know every game is different but what is most important role for jungle in the mid to late game?