Can I ask a bit more about your flatmates and people you're sharing with next year? Is it that they're not very nice or like "boring" - I know that sounds a bit mean but I can only imagine those two reasons as being the most affective on someone's happiness.
It sounds like you've got very unlucky with your accommodation. In my hall, for example, it's literally impossible to not make a bunch of friends unless you lock yourself away. You'd actually have to make more of an effort to not socialise.
So like what's your accommodation like? Are you in a busy hall or is it a bit dead? What about your course?
I'm not trying to help you make new friends, I'm sure you've tried a lot of things, I'm just trying to understand the reasons.
I feel for you, lots of people seem to go through the same thing and it was my worst nightmare before I came to uni.