hey smileymiles.
i can tell you that if you do get something, it will not be much and will be years before you see any dosh.
in the u.s.a. you would be a millionaire but spain is a very no sueing type of place.
i just saw a report on the tube about a doctor who operated on a woman without taking into consideration here blood pressure condition and the op went bad. she nearly died and is now an invalid and cannot walk (multiple complications during surgery).
the courts rewarded her a measly 120,000 euros

at any rate, if you want to go forward with this, you shouold find a lawyer in spain that speaks english (either a bilingual spanish lawyer or a british lawyer practicing here who speaks spanish).
if you contac the uk embassy or consulate here they should be able to give you a list of lawyers.
saludos & suerte,
jer...