Heavy armour is the easy route to take. Any old fool can wade into the thick of combat with an armoured, tank-like skin and not take too much damage obviously. Light Armour however, demands a different approach. Forget the stealth benefit for a moment and think in terms of where you're struggling, combat. Now with light armour you have a distinct advantage, speed and stamina. However, these advantages are rendered useless if you do not know how to utilise them. Your rogue character is primarily an offensive character as you've elected to dual wield. So you inflict mass damage but it comes at a cost, defence. Since you don't even have the ability to block you've made things harder for yourself than you need to. No shield, no blocking with your weapon and no thick armour to absorb damage. This is simply the build you've chosen. If you tweaked it just a little by using one weapon instead of two then you would gain the ability to block. The best perk in the tree is quick reflexes, which will enable you to avoid a power attack altogether. Perhaps adopt this tactic only if discovered and your initial duel wielding barrage fails to drop your foe. Rest assured as you progress through the light armour tree you'll be able to shrug off blows by even the strongest enemies and by this time no doubt your duel savagery will be lethal, you won't need to dodge/block. Good luck!