In all seriousness though, the situation that the OP is describing is different to being frozen out by her flatmates or low level nastiness from coursemates- both these do happen and they're not nice at all. However, usually the target isn't in any physical danger and I would say physical bullying of the kind seen in secondary schools is pretty rare at uni level (and the consequences are or should be very severe).
This is targeted harassment from one person, who she also lives with, and said person seems pretty volatile. I don't think trying to talk it over or trying to make things up with them is a good idea. Protecting your physical safety is always the most important thing.
That said, around this time of year, there are often spaces available to move flats in halls, so even if you just haven't gelled that well with your flatmates, it might be something to look into.