how old is the shock and did it just start to do this over time?
when u push the bike down hard does it bounce up and down a few times?
what brand is the shock?
the shock isnt that old its a nitrogen charged shock with resovoir
it wasnt this bouncy before...the swingarm also moves with it is it meant to do that??..so yes the bike does move up and down but only does this once
sounds to me like u busted ur rear shock it is time for a new one maybe look at ur swing arm bearings for the movement u may need to replace these too THE SEAL IN UR REAR SHOCK IS LEAKING IF A GOOD QLY SHOCK LOOK AT REPLACEING THE SEALS
Sounds like you've lost all damping ability ... especially rebound damping ... Time for a new shock ... IF you can wobble your rear wheel from side to side then you've either got buggered swingarm pivot bearings or wheel bearings ... OR both ...