Go back to broken valley and finish all the side quests and kill all the monsters you didn't to get a few levels and maybe better loot. I'm sure you didn't clear it, and btw archer is not an easy char until level 20 so don't be surprised your having difficulties. You can make sort of a paladin char, simply raise all stats around the same, use a shield, and take all the defensive talents you see, and just killing everything with jump hit (whatever its called). I always wanted to try this, and its going to be my next char, as I saw someone around the forum that did this and says its pretty good.
(Just balance all ur states, thou VIT and SPIRIT should be handled a bit differently).
A mage is also always a good way to pwn. Summon a deamon\ gost\ undead + your creature will put you away from the heat, while you cast your op magic missiles that (at higher levels) will 1 hit many things (especially with destruction and way of the battle mage and so).
Don't spend many points into VIT or SPIRIT (those states imo can be left at 15 both since you get so much gear with bonuses for them) and try to maybe put some into ur DEX or STR or whatever even if you don't need it for the added defense. If ur going mage focus on INT.