Ardent Mage in Hard mode

Hi I beat the game in normal mode with the Ardent mage with ease a while ago, and I just started playing in hard mode last week. I'm not sure if its just me, but the difficulty gap seems insane. I get the upper hand for the first 50-100 turns, but things just spiral down afterwards. The other factions expand their territory so fast, I can't complete the story quest for building a new city with 10 science. Also, it's really hard to manage my dust/industry/science since I have to use spells and pillars while others sabotaging my productions via espionage, pillaging and sieging. I tried to fight them back with spells and crafting items, but eventually, my dust runs out and my soldier just meltdown with a few hits like a cotton candy in water. Is there a good strategy to keep up with the management when playing Ardent mage in hard mode?