2003 PT Cruiser Transmission Problem

I was driving my Cruiser home and it jumped down into a lower gear wear it stayed till I stopped for gas and shut the car off. When I started the car it wouldn't move in either direction. It seemed like it wanted to go, but it was like the brake was on. I called my neighbor to tow me home. I started the car and put it in neutral so the steering and brakes would work better. The car would NOT move when running in neutral, but would move in neutral when the car was shut off. Like I said, it seems like it wants to move when in drive, but it acts like the brakes are on and can't move. anyone have any suggestions on this problem. Thanks, Stan :yikes: