How to go through the Dreadnought Vanguard with an easier time?

Playing a Ranger right now, and I feel like I've got decent defenses and damage, and I'm STILL having a hard time going through this area + Jamanra. I'm using all my life flask charges, even before each checkpoint, and it's frustrating!

Can't use any armour/evasion bases due to my class.

How can I make it any easier on me?

Slow with backtracking.
Clear an area fully to backtrack easier without encountering any "surprises"
If flask charges run out, portal back to the well to fill them up
try to get flasks with "Gains x charges per second"

Find or buy gear that has an affix of 2-4 life to hit (not kill). That way when you throw your lightning rods down and lightning arrow every little forked bolt that hits an enemy heals you. You can stand in the middle of a crowd fire away and never lose health. I currently get 9 heath back on every hit and breezed through the dreadnought, the boss on the other hand took me about an hour to beat. I'm a senior and my reactions aren't what they used to be. Hope this helps.