Just curious, do you utilize your PvP skills? All of them are amazing, really. Impulse Rush not as much as the others but the improved critical hit chance is a force to be reckoned with.

I would take a guess you are having trouble determining who you can take on alone, in a group, or who to go after first. As any melee dps, you need to "get in fast, get out fast". Mark the target you want to down, and wail on them with Fetter Ward. If they are getting healed for more than you're outputting, you should as a group quickly focus a different target or have someone distract/pressure the healer.

PvP is coordinated gameplay, rotations are important to a degree but there is a line-of-sight and approach mechanism that comes to you over time as you play. Knowing the capabilities of all the jobs helps quite a bit (knowing all their skills) and playing a pressure game works wonders.