What skills are you using Sub?
I am a lvl 11 Templar and have no issues with the quests I've been doing (course I have also had practice via Beta).
I pretty much use no stamina during fights, rarely Dodge (other than actually just moving) and anytime I would block I tend to bash which often stuns the mob - which allows for a heavy attack and knocking down the opponent.
The key to Templar is his burst damage, pretty much nothing should be standing by the time you drain your magic. Boss type mobs are trickier as you need to balance your resources a little more (though most the boss type mobs in solo quests tend not to be too heavy on damage)
My set up is 5 Heavy Armour, 2 Light (mainly to lvl up the skill line). Sword and shield.
SKills are:
Puncture (morph of first 1h&shield ability) - this reduces the mobs armour and magic resist which makes evrything you do hit harder.
Biting Jabs (Morph of first skill in Aedric Spear line) - This is the killer skill and my go to attack in all fights whether it be multiple mobs or single target. The damage is crazy good, even better if they are under 50% (if under 50% this is pretty much the kill shot on trash)
Reflective Light (Morph of first skill in Dawns Wrath) - Nice ranged attack, I often open with it, though do use it less and less these days as I prefer to use my magicka on biting jabs. I think I may respec later and make it the single target attack instead which does more damage.
Binding Javelin (morph of second Aedric Spear skill) - knockback with a decent duration, very good for taking a mob out the fight while you deal with the other, or more importantly great for disabling a tough mob (as usually in small groups of trash I prefer to keep them all close to kill with Jabs)
Breath of Life - my emergency heal, though rarely used which is just as well as I don't have much magic to spare, but has saved me a few times.
My Ultimate is from the Aedric spear line as it is dirt cheap and regularly usable for extra damage without resource cost.
The build does fine against up to 3 or so mobs, I open with Reflective Light to hit them all, run in close, Puncture the bigger threat (usually caster) then hit Biting Jabs, followed by another and usually everything is dead. If not I throw a few normal attacks or somemore Punctures if I have the Stamina.
On a boss type mob I keep Puncture on them, cast Javelin and maybe a Reflective Light as I walk towards them (skip the Javelin if mob is immune), I then follow up with a few light attacks and another Puncture, block if a big hit is coming, try to get him closer to 50% before spamming a few Biting Jabs on him - I usually try to keep magic high enough to have a heal spare.