I hear your pain! For a while I steered clear of the crucible as I was lucky to get a kill and kept getting my a** handed to me in every match. So went on the grind, story, missions & especially patrols to get my rep up (especially with Banshee 44 do the weapon tests for him) finally got my first legendary pulse rifle and then on my return to the crucible I started to get some payback. I am only an average player but have been getting into the top 3 here and there. So just stick with it, you just need decent gear.