Brakiri, you already complete isles, killed all mobs in both mines and both upper ground dwarf areas and you have only lvl 14???
Your bigger problem atm is to get 1st move with dragon fight (or try to change your armies to more melee like. Cavalry, knights etc..). If you want a 1st move then one of variants is to get forest spirits (i hope you didnt dismissed 15 units you got at the beginning of the game, anyway lake fairies will do too if you can buy them) and equip Agni ring. Voala, you have 1st move (question is how effective you can use it without high magic
)
If you cannot get spirits or fairies then buy some units with decent HP (knights and cavalry will suffice. You can buy them at the tent at 1st continent and then "grow" them up by using sacrifice while fighting "weak" mobs you didnt killed before).
Did you complete gremlin pocket castle? There are some dragon eggs at basement (and there is possibility to evade enemies if you cannot kill them).
There are tons of other variants. But question which i dont understand is: did you truly killed all mobs you can in areas i wrote about and if you did, then why only lvl 14?