1. Undergeared.
2. Need to work on CD - Dual a lot to know when you should use them.
3. Try diff spec.
Personally, against any marauders or assasins, I do not fear but welcome them for 1v1. Granted i have changed to hybrid tank spec from full tank afer 1.3(including Mods now), when I dual even the ones called "better or best" players, I have the slight edge to win the battle. Try Hybrid build, defensive stance and set bonus. With the CD used right, You may even win with at least 50% HP left. <-depends on RNG