i had a pvp necro once...lvl 73
Just like in your case at first, i was PWNT every game by almost every char.
he wore
shako(um)
shaft(um)
storm(hel)
wiz(light res jewl)
sojs/perf raven
40r/w charms
silkweaves
tgods
magefists
maras

max BS, bone armor
max lower res
other pts didnt matter

At first, all i did was get owned...i would kill a few, but it was probably a 10:1 kill ratio
i would duel all night trying to get my strategy down...the ratio would slowly climb...9:2 8:4 and so on...After about a week of dueling i would own
50%amazons
75% sorcs
100%pallys
90% barbs
75% necs
100% MA assns
50% trap assns
...the moral to the story is to keep trying and eventually all will be PWNT