Smelling burned rubber

When I was having a lot of symptoms and doing lots of 'researching' on google, I remember reading that smelling burned rubber or something burning can be a sign of a brain tumor.

Well, today while being 100% relaxed and sitting on the computer, I started to smell burning rubber.
I immediately started to look around the room and everywhere else, even went to the balcony to see if something's burning outside, but no...It was in my room. While I was in the balcony, I didn't smell the rubber, but only while sitting in front of my computer. Now Im worried, as you can guess... My friend didn't smell anything either! SO IT WAS JUST ME!

If it was a brain-tumor, I should be able to smell the burning rubber EVEN outside, right???
And considering I've had loss of hearing, black dots in my vision and such...Im seriously worried, AGAIN.
I thought I had gotten over all of this...