Thanks,I finished both quests,but now I'm stuck,and I'm really pissed

I'm playing on Normal,lvl18 warrior,I completed all quests and killed almost everything on Kordar,Freedom Island and Darion (except the Underground Sea,where creeps are a bit stronger..),and I moved to Ellinia,but there armies are also strong,a lot of them are "match",which results in heavy unit losses every single battle,and that is unbearable.I've got a dwaren army,consisting of 50 Alchemists,59 Cannoneers,8 Cyclops,7 Emerald Green Dragons and 164 Dwarfs,but I'm facing big difficulties,I've got only 3 side quests,all in Ellinia,and the main quest to go to the Land of Death seems like quite the challenge yet,as armies there are even stronger,and it's already difficult reaching a black book before that.What should I do? I really need some advice