HELP needed ASAP

I have a 02 Altima 2.5 I've torn the head off twice now,the second time round included the piston rings. On booth attempts there is oil seeping into the cylinders (all four of them) after Ive put the engine back together. I am at my wits end with this car. I'm ready to burn it and walk away. Has any one else had this problem. Please help.