Which class are you? I found that Engineer/Adept were pretty forgiving in most content even insanity. Completing the companion quests and getting some skills that worked off of the "opposite side" of the trinity helped (tech for adept, biotic for engineer).

That being said, Praetorians always suck.

I know that it's been changed for the remaster, but in vanilla you got more exp for killing stuff outside the mako, so I would try to get the killing blow for threshers and geth colossi on foot. That was stressful.

I am sorry, my mate. I leave you for a Krogan because you are not endowed as good for your species.

This is Commander Shepard and this is my favorite post on the Citadel.