Random lagginess since crash

Earlier crossfire crashed (or somthing) and once i got back on, everything was fine until about 5 minutes later. Then, no matter how many times i shot an enemy, they wouldent die. Also, if i got a headshot, it would kill them. And my AWM-c shot them, and about half a second later it would kill them. Also, when switching weapons, it takes about half a second to switch.

Help please!

P.S. I got a friend to stand still and i would attack him. I right clicked him with the Combat axe 10 times, he didnt die. I unloaded ALL of my m4-adv ammo on his chest, nothing.