Your skills are good. Your skills are very good indeed.
Your armor is probably wrong. Get armor with good resists and defense chance increase. DCI is the most important thing a suit of armor can have, and you don't have to sacrifice resists for a good DCI piece (note: DCI is only available on jewlery or artifacts). The fey leggings and ancient samurai helm both have decent DCI and have pretty good resists as well.
Your weapon may be wrong too. Get a fast weapon. It doesn't have to be the hardest hitting weapon unless you're hunting big game, but it does need to be fast. If you have 120 dex, any weapon with a speed of under 2.5 should be good without swing speed increase. Use a weapon with decent properties as well. Get your mana leech and stamina leech weapons, get your hit lower attack and hit lower defense weapons. They help a lot.
Your tactics may also be wrong. Be sure to use all the weapons in your arsenal, including lightning strike, a well placed enemy of one (make sure you don't use it where more than one enemy will be around, as all other bad guys to more damage to you when you have it cast), consecrate weapon, confidence, more confidence (my favorite bushido skill), evasion when you're in trouble, divine fury if you need to swing faster or your stamina drops too much... etc. My rule of thumb is that if I have full mana, I'm not doing it right.
But those are all guesses (except about your template being good. It is). In either case, it's some good advices.