I must be doing something wrong, at 1100 resists desecrate in Act 3 melts me fairly quickly (45k hp). Mind to link your character?
Pretty much what LeninGHOLA stated. I have 1000 life/sec as well as 800 life per hit (1.44 attacks per second). Serenity and seven sided strike pretty much keep me immune to all attacks for 6 seconds, and both pretty much give me back half my life (~15k hp, a combo of the life on hit and life/sec for SSS and serenity also includes a heal).
You're just lacking any real life regen at the moment. Trust me, it really helps.