Head bearings loose, tight, knackered ? My old ZXR suffered badly. probably due to my poor landing of wheelies.
front tire pressure (always worth checking),front tire defect ? Top/bottom yoke pinch bolts loose (scary), fork bushes knackered ? Brake calipers loose (very Scary) & as Gixer said dics warped or contaiminated pads. Good luck !
if any of the above proves useful we'll call it a pint !