It is sort of a penile issue as my scrotal skin goes more than half way down my penile shaft. I would rather ask on this forum than go to my gp and look stupid. I wonder if any other guy's have this issue?
It's not an issue. When you get an erection, a good portion of the skin on the underside of your shaft is actually scrotal. That is how your scrotum gets so tight when you are fully hard.
Without a picture, it's hard to say if what you have is anything unusual. What you describe could be something you're born with, or a complication of a tight circumcision though.
If you want to add a pic, you need to be on a PC or laptop with a large window. If you are, then you should see some extra icons towards the top right of where you type, and the right hand icon (which I think is supposed to look like the sun over hills) will add images.
The pic I've attached here shows the icons: