Templar - Summoner build - Advice needed!

Hello,

after a break from PoE I returned to this aweseome game and decided yesterday to continue my Templar-Summoner. After spending the passive points and a few promising testruns in low-level area I was shocked when I encountered the first boss, this guy called "Kole" (?) in the Lunaris temple.
He ripped my army of 8 Skeletons, 7 zombies and 3 spectres (I have the two summoner legendaries, the sword and the shoes....which should normally give you an insane boost) apart within seconds, with still 90% health left. I am using "discipline" as aura and "enfeeble" as curse.

Long story short: What am I doing wrong?

Here is my current build:

http://www.pathofexile.com/passive-skill-tree/AAAAAgUABVsWbxcvGmwkqiSwKpg26UbXTbldxoCkhWCG0YhAi4yPRpAzm6GdrqaspwiqxLUEzLzZC9rd4XPjauQi7SD31_qA-tI=

Any help or advices would be appreciated, thank you for reading!

You need higher level gems most likely. ... also- what are you linking with your summons?

Spectre lvl 6 -> minion life lvl 8 & Added lightning damage lvl 8

Skeletons lvl 8 -> Minion Elemental resistance lvl 6

Zombie lvl 9 -> Minion life lvl 8 & Minion damage lvl 6

All of the gems are at / close to my level, but unfortunately I only have 3xlinked-gem sockets in my current gear. Should I try to get more 4-linked / even a 5-linked breast?

Currently I am running 4 4 links and I'm in merciless act 2 with all gems maxed to the same lvl I am as well. .. bosses are brutal, mini bosses and everything else are easy as pie. A give link chest would be huge, but unless you have minion life gem, or something along those lines, you are going to have the same problems. .. what we both need is to have lvl 20 gems.... then we will be good, but until then, gotta party up with other people to get the most from our little weaklings right now :)

I already feared that grouping is the only solution for this kind of bosses...but I prefer to play alone. Guess I will stick to my marauder then.

Thanks a lot for your answers!