I have the car in the air does the supporter wall of the housing have a black plastic part to it from looking underneath.Have you re-adjusted the long linkage (at the gearbox end)? If not, it should work perfectly. A very noob question: have you fit the gear lever housing (the big white plastic housing) correctly? The supporter wall should be on the passenger side.
You might not have a problem, put the car in neutral, undo the linkage bolt sleeve pinch bolt underneeth. Adjust it which ever way you need to. ( selector rod ) Redo the bolt up , not to tight or you crush the rod. And see if you have all gears.