I'm having a similar problem. I'm using the wbtb wild technique. I feel all the telltale signs, numbness, vibrations, hypnagogic images, but I can't ever get that transition to complete. I just lay there focusing for hours on end. The hypnagogic swirls never materialize into anything. I would gladly accept a DILD, but I never attain lucidity. I just have very vivid dreams that I recall and write in my journal but I never know they're dreams until I wake up.