On a healthy engine the oil breather should spend most of it's time acting as an INTAKE to the crankcase, flowing air into, around the crankcase, and then out the PCV
On engines that typically were getting worn, with breathers linked to the air cleaner bonnet, a tell-tale sign was excessive oil buildup in the air cleaner.
First thing I'd do is make absolutely sure that you have a clear 3/8 hose path to the intake, that is, pull the pcv out of the hose and it should instantly kill the engine unless you have it revved some
Next change the PCV just because they're cheap.
I suspect you have a severe blow-by issue. You may have a cracked piston, broken rings, or the engine is just tired.
This can also be caused by a head gasket blown in "just the right spot"
What is your perception of the engine overall condition? Does it use/ show oil anywhere else like the exhaust.