With the engine off and the machine in gear, will it roll at all? Is there any noise when you put it in gear and let out the clutch with the engine running? When it is in reverse, you say in moves but slowly, does it seem like the clutch is slipping? A slipping clutch is what I first thought. It could be the clutch push rod haning up, the engagement lever could be bent or damaged.
Yours truly, sincerelly, love always, Josh aka The DirtDemon.