My Hex 3 came with some cord to attach to the apex loop, which should be staked to the ground in the direction of the wind. Not sure if that would help with the pole bending, though, as this is probably more to do with pressure form the sides of the tarp pulling laterally on the pole.
I too have a hard time getting the Hex 3 low to the ground while keeping it taught. I have found, however, that I can get a taught pitch if I first place all 6 primary stakes first, using my trekking pole set at 60" to make 6 triangles in the shape of a pie. It's possible that if you set your pole to something smaller, say 57", and do the same thing, you may get it closer to the ground while still maintaining a taught pitch. You've got to be pretty precise with your stake locations. I've never been able to get it really taught just by eyeballing it, which is why i use my 2 poles to 'triangulate' the exact stake positions.
But even then, I'm not sure that would have prevented pole bending. Again, I think it has to do more with lateral pressure, rather than wind getting inside. As far as it being breezy inside, you may be better off bringing a bivy or overbag in those conditions.
One final thought: did you try angling the pole in the direction of the wind? That would take some of the lateral stress off the pole.