avb3's sense of urgency in addressing the issue is bang on. Sounds like your cutlass bearing is shot and continuing to run under these conditions may result in scoring the shaft which is a spendy fix.
You will have to pull the boat
to address the problem. You will need a bearing puller to get the old one out or you can cut the rubber material with a sharp knife and try and worry it out but the puller is a better tool to use IMO.
Take the old one into a marine
shop to get the OD/ID sized right and drive the new one in with a wooden mallet.
While the shaft is out, have it trued to make sure it isn't bent. If it is bent and you re-install, it will eventually cause you problems.... cheers, Capt Phil