Mid-game apathy/fatigue

[Metathron]

I'm a level 25 warrior on impossible, and am currently kind of bored with my game. My army consists of ogres, trolls, paladins, archmages and shaman. This lineup was very exciting up until about the early twenties. But now all the enemies around me are either absurdly easy (1st four islands) or too tough and the trial and error battles with strong (and above) enemies have become tedious due to the frequent need to reload because of losses (still some 20 battles to attain Grand strategy).

So, has anyone experienced something like that? What (if anything) did you do to make things interesting again, change your troops, your strategy, something else?