The business and investment opportunities that would be flying through my head if I had aquired 15 x £150k (£2.25m) would be numerous. I would be dreaming of ways to make the money safer and vastly grow in size.
Buying a House and then a nice car is what you do when you win a few hundred thousand. Winning nearly £2.5m falls into the catagory of changing my life, and the lives of those around me. The list of people I would make financially comfortable is a long one. The fact that you are thinking "LOL, im gonna buy an expensive car, cos I can, LOL" says not only a lot about your financial sence, but also your outlook on life and personality.
IF the money has made you this squanderous then I feel sorry for you, but the £20k debt makes me thing you think that your poor attitude and outlook was a pre existing mentality.
I wish good people won money.