I had some of the same issues while levelling (maybe not helped by the fact that I mostly play resto in BGs once at the level cap, so was rusty on enhance when Mists started).
Based on advice from (I think it was) this board, I made a few changes for survivability and it made a huge difference.
Glyphs of Healing Storm and Feral Spirit will help you get through multiple attackers much, much, more easily--just make sure to pay attention to when you need to use your maelstorm procs on heals rather than on lightning, and don't be shy about popping your wolves, their cooldown isn't that long.
Remember to use your tier one defensive talent (or go into Nature's Guardian, which is automatic), and if you add in Ancestral Guidance in tier 5 then you have periods where you can survive pretty much anything (pop that and your wolves, and most likely you can simply use your maelstrom procs for burst, as that also helps on your healing).
Our totems are no longer long term passive things, but they all serve purposes. It took me a while to get used to remembering to drop them at the appropriate time (and keeping an eye on the cooldowns) but they really do matter. Capacitor totem may be annoying, but that stun can buy you a lot of time, healing stream totem is yet another short duration heal when you need it, fire or earth elemental can help deal with crazy situation or 'quest boss' type foes, etc.
In the early Mists levels I had mana issues at times, especially if I was using fire nova much and had to throw in an emergency heal or two, and I did find myself using water shield at times, and making sure I had food with me that would restore mana (the milk from vendors is decent, tops off your mana in seconds, or you can wait for the 10 seconds for the mastery boost) and not be shy about using it. By about level 88 or so the mana problems mostly went away--and as I'd adopted the other hints above the need for emergency heals (not procced) went away, which helped too.
One thing that can play into the mana issues is your hit and expertise. Reforging leveling gear is annoying, but if you find you have really low levels of those two it might be worth the effort, increasing your damage, your procs, and your mana regeneration. (and I surely know how annoying re-forging is, looking at my current enhance gear I clearly have neglected to reforge it in ages (but I'm 98% just questing, and even on Thunder Island it is not too demanding, provided smart play)
ETA: I just noticed that you are still at level 83. You should be able to start finding Mists greens on the AH, which will do wonders for your iLvl and hence how well you survive. Easiest step to take :)
Edited by Vashkiri on 4/18/2013 8:09 AM PDT