Need help with a melee Warlock

I’m new to Grim Dawn and my first character is a warlock. My character started off pretty well but now I’m having a lot of trouble. Every boss is absolutely demolishing me. I feel like I have to constantly chug health potions just to keep up. I also have no idea what abilities I should be investing in. My health regeneration is pretty good but it seems like large groups of trash and bosses just melt through my health. I need somebody to show me what abilities I should be focusing on and how to do better in combat.

Here is my character at level 32
Physique: 534
Cunning: 382
Spirit: 403
Health: 3271
Energy: 2076
Armor Rating: 243

Skills and Abilities
Occultist:
Solael’s Witchfire 12/12 Second Rite 1/12
Sigil of Consumption 7/12 Destruction 1/12
Blood of Dreeg 6/16
Doom Bolt 3/12
Possession 1/12
Arcanist:
Iskandra’s Elemental Exchange 1/12 Overload 1/12

http://www.grimdawn.com/forums/showthread.php?t=49277