My description make it seems like it is the urethra, but it too big to be the urethra I guess because it covers up too much area.

There is this meaty thing inside my vagina. But it's not in the middle. It's actually a little bit higher than what is seems on the diagrams. It's not something that covers up a hole, its kind of puffy, there is a hole in it (but is horribly small, almost none) , BUT when I wanted to explore myself ...