While self defence ect. Is absolutely worth considering, you ideally don't want it to get to that stage.
From the sounds of it, your university is doing the standard beurocratic arse covering bullshit of hoping it'll all go away. That's because dealing with the problem is going to be a pain in the arse for them.
One thing, as well as the other suggestions here of course, to try is making yourself a bigger pain in the arse to them than dealing with the problem will be. Document and report everything. Keep on complaining until they are in the position where if (god forbid) the worst would happen there'd be massive a pile of reports about him and they would definately lose their jobs. Then they might step in.
Trust your instincts, don't let them make you feel stupid and document/report everything.