When I was a little girl, I believed only wealthy people owned cars. I also believed only obscenely wealthy people owned homes. I tell you this only so you appreciate I've come from a similar socioeconomic environment to that of you and your family. Like yourself, at a relatively young age I came into a little money. It wasn't anywhere as near as much as you've won, but it was enough to provide some options. I could have blown it on expensive holidays and investing in financial schemes I didn't understand and couldn't manage, but I didn't.

You're going to give your boyfriend half of the money irrespective the advice you've received here to do otherwise, so we'll go from there. 1. Pay off all your debts. 2. Buy yourself a home. Do not buy a mansion or fixer-upper. Buy yourself something which requires little or no work, and most importantly, assume your money will be gone in a few years and you'll have to cover whatever rates and expenses associated with your home on a relatively small income. In other words, don't buy a property which you can't afford to maintain on a low income. 3. Buy yourself a car of some description. Buy decent, but not too expensive. You should be able to get a very good and reliable used vehicle for under 10K. 5. Furnish your home with the basics. Don't buy new. Buy good second-hand wherever possible.
You won't have a lot left. When your relatives ask, tell them you have much less left than you actually do. I can't tell you how to handle them at that point, but whatever happens, you'll have a home. Unlike other members of your family, you'll never have to live in a caravan or feel the fear of the roof over your head being threatened because you can't make the rent.

I own my own home (it's a actually a villa). I will never be destitute irrespective of what life throws at me. You have the ability to put yourself in that position.