Dying a lot in Act 5. Any tips?

I just beat Act 5, and literally kept getting one shot within 1 second if I was surrounded by a group of enemies. I feel like my gear isn't -that- bad. But I'm probably wrong. What should I be upgrading?

Take life nodes in the passive skill tree?

The first thing that stands out to me is the lack of life on your gear. You've got some but you could certainly have more (none of the chest for example, unique belt without any other than the strength, etc). There's also more life nodes you could be taking on the tree over offense (such as the starting nodes for Templar). However, those nodes are only strong if you have a lot of flat health to scale them.

Getting more life on gear and getting more life nodes would help. Beyond that, make sure you are capping your resistances. You're playing a totem build, so try and let them do the work and kite if possible.