If you start thinking that the AI is too easy,
Edratman's mod will take care of that. It's in MA only and also incorporates Better Independents mod, also worth a look if the AI doesn't challenge you.
If you don't think you're not having fun with your current game, don't feel afraid to start a new one. If you want that feeling of satisfaction for actually winning and not just dominating, enable Victory Point victory condition on game creation and make the game end once you've conquered all (or most) capital provinces.