2002 Ford Escape More than steering issues

My car has been making a loud noise, like a jet flying overhead, the belt and pully system were recently changed but the red circular with three bolts thing below and across from it seems to be vibrating and making that noise. When I turn on the AC it gets louder. The AC had 2 pounds of freon pumped into it just 2 weeks ago but now it's blowing hot air again. Then the battery light came on and power steering went out, but the car was still running. Help me, please. I'm just about completely broke already and cannot afford to get taken for a ride at the local shop. I have 'total car idiot' stamped on my head! Thank you!