So it's more about gear then story? I am doing ok as a healer in story mode, does it get a lot worse in hard mode?
If it's the story that interests you, the order is Directive 7->Ilum Planetary Quest->Battle of Ilum->False Emperor->Kaon Under Siege->Lost Island->[Lv. 55]CZ-198 Planetary Quest->Czerka Corporate Labs-> Czerka Core Meltdown
I included the planetary quests because if you're interested in the story, you'll want to do them before their following flashpoint, because they set up the scenarios.
Edit: Also, in terms of story order, if you're already on Makeb, then you're already out of order with the story if you haven't completed D7->Lost Island yet.