HELP! Vagina isn't normal?! (includes drawing of vagina, not an actual picture of it)

So I have this problem. (Please don't call me dumb because I wasn't exposed much to this)

I have literally looked up so many diagrams of vaginas to see if ANYONE has anything like mine, but no one does.

Below is a drawing I did (a very rough sketch) to show my concern.

So as you can see, there's a bit of skin that cuts across horizontally in my vagina. It makes it feel like my vagina is two separate holes, and I am very confused.

I had a guess that it was my hymen, but it isn't, because 1) the hymen isn't as visible as this skin tissue, and 2) my hymen is broken from a rape incident.

I have no clue what this skin is.

Whenever I masturbate, I would finger the part of the vagina that is closest to the pubic mound, because it felt more loose than the part closest to my anus, and would feel good. Whenever I fingered the part in my vagina closest to my anus, it would feel very uncomfortable and it would hurt.

I have become worried, and this wasn't taught in my Sex Ed class. They taught about the anatomy of the female reproductive system, but this piece of skin was never mentioned, nor can I find any stories or diagrams with this included, as I've previously stated above.

I am not going to mention this to my mother until I get feedback from the Glow community first.

Should I go to the doctor? Is this normal? Does anyone have anything like this?

HELP!