You're trying too hard. Even getting excited when you approach out-of-body experiences, even getting annoyed or frustrated, will ensure that you don't leave. If you can manage to go through the routine of an out of body meditation, but somehow also manage to trick yourself into not expecting anything to come out of it, and remaining calm and uncaring when the weird things begin to happen, then you'll succeed.
With that said, you could also try Active Imagination. It's easier, and might even be more helpful with what you're looking to do.