You may have 1.8 TB of free space but you have 16 GB of RAM which is the actual memory. I suggest you run Activity Monitor (can be found in /Applications/Utilities) for a bit and check the memory that is being used there. A memory leak could be the case when an application uses more and more memory the longer it runs without doing stuff that needs more memory.
With that said/written, I think t would be very helpful to know
OS version (have you upgraded to El Capitan?) and
the CrossOver version you are using
And, as the people here in the forum don't work for CodeWeavers and so have no idea what you were told and have done already, it would be helpful to know what "plist and support deletes" you did do.