I just did Esseles on my level 12 Consular earlier today and felt like my threat was nearly zero on all fights. The healer I was with (there were two of us) was pulling mobs off me when he'd help with dps. Are there tank specific abilities that come later on? Anything I can do to help with threat?
Also, I am stacking Endurance and then Willpower...is this correct?
Well, you could reach a higher level. That would help threat a lot.
At level 12 you have basically nothing to help you tank. No taunts, no AoEs without knockback, and you don't even have the tanking stance. You don't have increased survivability/threat talents. Wait and it will come. JKs and Troopers aren't tanking well at level 12 either.
Like Torethyr said, it gets better at 14 when you get your tanking stance and then as you gain abilities from there. It isn't WoW though, you have to work to hold threat as I'm finding when tanking for guildies who dont like to follow my target