Your general practitioner would be a good place to start. If you need to see another doctor the GP will refer you to them.
what doctor should i go to?
The itching in your vagina could be thrush, the white discharge doesnt always present.
does the 'bubble' feel sore? and is there any bleeding from it? it could be a hemorrhoid, so you'll need treatment for that.
Dont be embarrassed, nurses and doctors see all kinds of things everyday! you feel uncomfortable, so dont stand for it and go see them.
as for the pinworms, as long as you dont sit on a seat naked! just wash your hands thoroughly after coming into contact with your bottom to avoid re-infection and infecting others.
remember, doctors dont judge, they are there to help no matter the problem x
The vaginal itch could be from a yeast infection.
Not trying to sound mean, just trying to help you overcome your problem before it's too late.
Good luck