Can't swing or attack mobs and right hand is invisible

I was playing normally till I switched skin and my right hand went invisible and I can't swing it in invisible air nor I can't attack mobs with sword or empty handed, I can open doors or red books but I can't swing it or see it or attack mobs with it, plus when I crouch he stands up by himself in water unless I keep pressing and holding crouch he stays crouched in the water.