Looking at your warlock you haven't played a ton of crucible yet and your rift kd is a 1.21 so that's showing positive signs that your game is stepping up every time you play! You should try playing some crucible on your hunter or Titan you may find you play better as a different class due to all sorts of things like movement, supers/grenades even all the different melee attacks. Hey I'm not the greatest crucible player myself but I've played enough to be able to say the little I've said I guess :)