Want to ramp up the difficulty a little? Just take off all of your gear and do those quests. I ran into a bug where my modded gear would reset it's stats every time I zone transitioned, so effectively doing everything naked. Walking around with like 33% lower hp than my companion, friends, getting slaughtered by everything. Took me some time to figure out what had happened.
Still, I was able to complete my story quests, survive group missions and flashpoints.
In other words: if I can unknowingly do the game naked except for a few pieces, I'm pretty sure the difficulty isn't as high as you make it out to be. Just have to figure out how you need to respond the situation: maybe a different companion, maybe some CC/stuns, maybe just taking the time to learn your class overall, it really does help in the end. This isn't a FPS where you tap your aim button to quick-target and 1-shot the world. RPGs typically require a little strategic planning, and a bit of trial-and-error!