Hello, I have some bigger Problem at the moment,

I have booked a flight from December 20th to January 10th, but instead i would rather fly around 7th, to spend 2 more weeks with my girlfriend over Christmas.
The problem is, i cannot cancel or change my flight. So my only option would be to book a second flight, and waste the other flight.

So my question is, is there any way, that i can get a refund of the other flight or possible change my flight without spending 200 euro for a new ticket? I'm a student so flushing down 200 euro down like that is really a huge amount of money for me, i realize it is my mistake, but is there any way that i could get this any cheaper?

Would writing to the airline and explaining my situation help anything?
I also read that there are sometimes full refunds given if there is some medical problem, but this kinda only works when you want your flight on a later date

I'm thankful for any advice any of you could give me


EDIT:

Airline is KLM
flight is VIENNA <-> AMSTERDAM