oil pressure guage is at zero, lifters tapping and antifreeze coming out of a hose on right side of radiator

It doesnt do it all the time but its becoming for frequent. When my oil pressure gauge drops to zero, my lifters instantly tap and the engine sounds loud like a diesel motor. When pressure is fine, it purrs like a kitten. Also truck has been running a little hot but the needle is buried in the red. When it runs a little hot and during the tapping episodes, when u turn truck off its smoking in the front and when u pop the hood, there is antifreeze around the opposite side of where the cap is, near a hose. The overflow is full, however ive been having to put in a thing of antifreeze about every 3 weeks. I am not sure if I have more than one issue going on here or if its somethinig that will fix all of this. Please let me know your thoughts. Thanks!

Aaron