You could have a transmission problem or possibly maybe just the in the shifter system. Is the Malfunction Indicator Light (MIL) on? If so, there's data and trouble codes stored in the controller and would help for diagnostic purposes. A mechanic with a scanner could read the codes and data.
Here's a directory link for you:
...e been having a super loud grinding sound for a year the mechanics shop now telling me its the transmission bearing and wants 1200! I don't have it put so much into this vehicle but stuck in it now 16 s...