Canadian here with several million in assets. In the event you're also in the great white north, perhaps I can help with some of our unique financial rules and regulations.
First off - Congratulations! This money has the potential to make a real difference in your life and that of your bf.
Unfortunately, there is no amount of money that can't be spent.
This is a life-changing win, but is not the kind of money where it would not even be a question about sharing. (I'm not sure that amount exists.)
You are not being cold if you don't give everyone a little something. Indeed, that's probably the only way that the money will last.
I think it's great that you're standing by your word and splitting the pot with your bf. I'm not going to suggest that you not share. I think if that was even an option, you would have said so in your initial post.
Next - Your initial plans are really solid - pay off debts, finish education, pay for dental work, and treat yourself to a (reasonable) trip to Thailand.
When that's done, consider buying a house outright - perhaps buy it jointly with your bf. Not only will that dramatically lower your cost of living, but you can draw on the value your house in the event of an emergency.
Canadian context: If you buy the house yourself and he contributes to bills, he will be entitled to 50% of appreciation of the house as your common law partner.
After that, you can look at investing the money. This does not need to be complicated.
Canadian context: Tangerine (formerly ING Direct) has a fund called the Tangerine Balanced Growth Portfolio. Rather than picking and choosing companies, it has 1/4 of its money in the Canadian stock index, 1/4 in the US, 1/4 in the rest of the world, and 1/4 in bonds and other hard assets.
More CanCon: If you want to also have the benefit of a financial adviser, I also strongly recommend Mawer Financial (www.mawer.com), based in Calgary. Look them up - they've won a ton of awards and are regularly mentioned as one of the few mutual fund companies that regular beats the stock indexes.
(Beating the stock indexes is very difficult for financial companies to do, even though it amounts to 'be better than just throwing darts at a stock market page').
If you still want to do something for your family - and limit how much they hassle you - you should consider setting aside some money in an emergency fund, which you can use in the event that someone in your family is in urgent, desperate need.
(Eg. Pay for cabs to take them to and from cancer treatment - the treatment itself being paid for by Canadian health care.)
Perhaps they'll realize that this is what really matters - to be able to look after those you love in their time of need. Or perhaps not, and they'll still hate you. But if they do, that's because they're jerks - and ultimately that's their problem. But you can rest easy knowing that you've done something meaningful for them without feeding the insatiable beast of greed.
I'm glad to act as a resource if you'd like someone to speak with about this, or just about investing in Canada. If so, send me a PM.