I am level 38, so you have quite a few levels above me, but i will tell you what i have learned so far. What i end up doing is always uising Dorne to keep me healed while i fight, and i make sure she is on medwatch and not dps mode whatever its called. I also use my cryo grenade and that aoe pushback to interrupt casts of long abilities that always seem to do significant amount of damage. When i am fighiting elites I also have a medpack ready just in case i need to use it, but i rarely do and use every ability that allows me to regen health or take less damage.