Can someone experienced give me some advice

I'm level 70 and this is my first character. I'm looking for some advice on where to go next on my skill tree. Here is my current build. http://www.pathofexile.com/passive-skill-tree/AAAAAgEAAnEEswUtDjwPzBQgFE0WbxiRGS4ZhRo4HRQhAiFVJKon7Si1KvYyCTKJNuk5DjpSOthAoE3YUEdQUFRJValVtVXGVgRX4lhjWfNfP2BLYIhhUmaecql07Xbnd-V673uMfNmDOIZgjHaMz49GkFWezZ_LogCmZKcwp4SpaKyqud3AGsEExtjJmM9l0NDUj9w93sHfv-Nq5K3nUuw47w7vTu988B_yL_Pd9kj3vvrS_c8=
The main skills i use are infernal blow, sweep and molten shell. My health is about 3.4k and i have max elemental resists. My armour only stops about 15% damage though which i think is quite low. So i was considering putting some points into armour passives, i already put one in down the bottom of the tree. But then i thought i could also go to the health nodes in the middle. What do you think would be best, some armour or yet more hp?

Get all the hp nodes you can.

But his health isn`t bad for lvl70.
And he just took 1 armor node.

I would go through to Steel Skin and then procede to more health nodes.
(and maybe get a chest with more than 1000 armor)