Olive oil is extremely bitter - has it gone rancid?

I recently bought some organic certified extra virgin olive oil from Tunisia. However 1) It is a cheap brand (only $10 a Litre) 2) The manufacturing date is Dec 2012 so its over a year old 3) It is packaged in a heavy, dark green, glass bottle and states it is best before 36 months from date of manufacture 4) It is extra virgin and organic certified by EcoCert 5) It tastes extremely bitter (almost as bitter as bittermelon - if you've ever tried it )

Has the oil gone rancid? Should I throw it out?