Rear derailleur won't shift at all..

I can pedal and manually move the mech to small or largest cog with no problem..

But without manually moving it, when just shifting gears it won't move..

I see the cable moving when shifting also inching forwards or backwards..

I did however fray the end of the cable really bad, I then cut it off making it shorter ( could that cause it not to shift at all ) ??

The tension barrel at the shifter is missing ( if there was one there to begin with) but there is a tension barrel at derailleur so I don't think that would be a problem either..

Would a bent hanger or derailleur cause it not to shift at all?

Just trying to figure out the problem here to avoid going to shop as I'm on an extreme budget and have $60 to my name.

Derailleur is a Shimano Acerra
3x8 drivetrain

Huge thanks in advance!!