Jeep - Grinding/Whining

I have a 2002 Jeep Grand Cherokee Limited with 97k. Today while driving (going abt. 40-45mph & with the AC on), it started making an awful grinding sound & seemed to be driving differently -- almost felt like I blew out a tire. I turned off the AC & pulled over & all tires were intact. I started driving again & the sound continued. Then, about 1-2 min. later, it stopped, but the engine sounded like it was whirring/whining/whistling (?). Fast I went, higher the whir/whine/whistle. It's an automatic & was shifting fine. I got it home abt. 10 min later & looked under the vehicle. There was a slow drip of water (which was hot) coming from the front passenger area. (& turned it off as soon as the grinding began). I opened the hood & everything looks intact -- no antifreeze spray, etc. Ideas??
Thanks, Jessica