I'm having an oboe emergency. My E key - not the little key above the E key - is leaking, and I have absolutely no idea how to fix it. Every other key is fine, but the cigarette paper comes right out of this one. Help, please?

I would take it to a reputable double-reed technician or ask your private teacher

As OboeLover says it's best to let someone who knows sort it - something like that is usually very quick to do unless the pad needs reseating or replacing. Maybe one adjusting screw needs a minor tweak. Do not just start fiddling at random as so many keys on the oboe are interconnected & you can easily make things a whole lot worse!
What make & model is the oboe? That would help in suggesting a place to start.

^ Take it to your teacher or double-reed specialist.

I lost a pad, and my dad decided to fix it. (My parents don't believe me when I say, "I have to take this to the shop.") Well, it ended up costing $117 in repair just because my dad decided to fix it. Luckily, we had insurance, and we didn't need to pay, but still.