Your problem is that you don't know how to kite properly. Rogues and warriors are the two easiest classes for a hunter, especially in world pvp. If you can just get them into a trap, you win. Say a warrior charge you in battle stance and you feign death trap him. Now you run away with cheetah and keep a good distance all the time while your pet is harassing him as well as you run/auto shot/run etc. Same goes with rogue. Against rogues make sure to have serpent string so that they can't vanish. If rogues uses sprint to chase you just stun them with pet and keep running. As soon as they realize they can't get to you and turn around, you turn around as well and chase them. Easy as that.
I personally prefer BM in pvp as opposed to MM. Intimidation and bestial wrath are extremley strong abilities.