Don't fight, run.
Alot, and die, alot.
I will say that ME is rather old school in the you are dying a metric fuckton way. Most of the combat sections in the game are kinda puzzles that you have to figure out, and 90% of the time your best bet is running the fuck away, Faith may be able to pull off Ninja jumps and shit, but she is still weak to the all powerful shotgun to the face.
Still, once combat clicked for me, it wasn't too bad, it's all about singling an eenmy out and using momentum against them.