Yeah, I used to be suspicious of whether or not I'd find it. Didn't help that my hands are small and, while my fingers can reach it now that I know where it is, it's tiring to try it with my hands alone, which might have been part of the problem.
It took ten years before I found something that alerted me to its location without any ambiguity: the Bent Graduate
. This toy slammed right into my G-spot as if to say, "It's right here,
you moron!" Now I can find it every time.
Keep trying different things. New positions or certain toys might make it easier. The precise location and size of the G-spot vary from woman to woman, so be patient. It also helps to be as aroused as possible - it often swells and becomes easier to locate with arousal, so do whatever it takes to get yourself in the mood and it might aid your search.