Hi Spade

I am 29 only two years older than you. I know how you feel especially about being so young.
Right at this moment you have got yourself into a state of panic over this which is understandable. Calm down and b r e a t h e. You don't actually know if this is the real deal or not yet.
I think you should go and see your GP. There is no alternative but to do this. If you don't and its nothing you are just going to continue panicing and if it is something more serious than hopefully you will have caught it early enough. The longer you leave this, if it is cancer, the worse it will become.
Be brave now and take the next step. Everythign is treatable but you need to get it looked at real soon.

Wishing you the best of luck
Sweety