Some people like earning ISK as it’s only goal.
But for many ISK is just means to an end. Personally I enjoy earning ISK from time to time but wouldn’t want to spend all my EVE time doing just that. What I do enjoy is trying new things, using ships in PvP fights and other activities. I need ISK to fund that, which is why I make ISK.
It sounds to me like you get bored by making ISK without a further goal.
Have you considered trying to do one of the many things in EVE that you need that ISK for?
Buy a fun expensive ship, use it, lose it to something stupid, do it all again? Then you have a reason and goal for all that ‘ISK earning’.