Hmm sounds familiar. I had the same problem happen to my 83 SD. Found out that the E-brake shoe was stuck locking the left rear wheel preventing it from reversing, but it was ok to move foward

Check your e-brake shoe and all the e-brake components.

__________________
Current:
05 E320 CDI
07 GL320 CDI
08 Sprinter
05 Dodge Cummins
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Previous
2004 E55 AMG
2002 C32 AMG (#2)
1995 E300
1978 300D
1987 300D
2002 C32 AMG(blown motor :[
1981 300SD
1983 300SD
1987 300SDL
2002 Jetta TDI
1996 S420
1995 S500
1993 190E 2.6
1992 190E 2.3
1985 190E 2.3 5-Speed