I'm stuck on the Xiedu map near the end of the 4th month.
...
In general, the map seemed just very difficult before (like any other map by Season), but now it has become insanely difficult.
I don't know, Xiedu didn't impress me much, although it took a considerable amount of real-life time. After reading in the comments on heroes4maps that someone completed it in 60+ months, I decided to play it just for fun - and I also managed to complete it in about 60 months. Just don't speedrun, and there won't be anything too difficult.