I am having a hard time progressing. I have leveled my heroes as far as they will go, promoted them as far as they will go, and went through every hero's gear and got all of them geared up, to the point i need to level up before i can gear them further...and now I am trying to progress through the campaign, but I keep getting defeated. It tells me to find better gear, and level up my heroes to progress further. Do I just need to keep running prior campaign points to try to level further?
There are some bottlenecks like this in the game. You might look at what gear your heroes will need in the future that you can currently get in the campaign and focus on those locations to level up more, that way you are killing two birds with one stone. Also, increasing your heroes star rating has a big effect in power and survivability so continue trying to get more stars on your heroes.