I have exactly the same problem, someone told me to do the conall valley's quests but thats just for like 1-2 levels then I am stuck again. I have done like everything in Khopshefs and Zelata...
Just turned 30 myself, and did the next step in the destiny questline. Am an Aquilonian. So i've spent 20-30 in Wild Land. Not sure where to go at the moment, maybe border range? or should i go over to Khemi/Cimmerian and do the quests that i can do there?
I also got to 30 in wild lands then moved to kheshatta province to 34, sewers in tarantia and border ranges for 36 (don't forget to visit poitain/lotus swamp for 4x10k exp;>), planning to hit 40+ tommorrow on connalls/rest of zelata and kheshatta.