2005 Dodge Caravan I dont Know what the problem is.

Hello. Im eric. recently i was driving my moms caravan and it has never failed it has always been reliable. I didnt notice til after it stopped that when I used to shift the gear to reverse it thums hard and it reverses. The Day it stopped i cranked the car up and I shifted it to reverse and it was made a rubbing or a scrubbing kind of noise.. i didnt think much of it so i proceeded. I got to the gate of my apartment and the noise got louder and it just stoped moving on me. So i put it in park and turned the car off and cranked it back up and no matter what gear i put it in it makes the noise. I know it is a transmission problem i just dont know is it a part of the transmission or the whole transmission. Can U please help me..