try to do it like what the rugby guy does always. Lie down on a bench without your head touching on the bench, ask your partner to push your head down and you try to fight back at the same time, and then try to fight your head back up while ur partner give you resistance. 10 sec up and 10 sec down. Do it front and back and sideway. Or you can buy the stuff where you can put the plate on the rope and hang it on your head and do the same thing( i dun know whats the name). Do it 3 times a week. Keep it up bro