As dlhotka mentioned, you are likely bumping into the issue as debated in that mega thread.
A summary is here:
The good news is that there's a hotfix on the way (hopefully by Monday).
As a workaround you can temporarily change your VM RAM to only use 2GB of RAM.
Wil| Author of Vimalin. The virtual machine Backup app for VMware Desktop Products
| Vimalin : Automated backups for VMware Fusion and VMware Workstation Professional
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| VMware Wiki at http://www.vi-toolkit.com
Fusion 11.1.1 is just pushed live. We have a mitigation fix for the VM performance issue on macOS 10.14.6 with this release.
Root cause for the VM performance issue, is “the behavior of paging memory from an unlinked file.” Check KSC’s updates in community if you want to understand the technical details. And this one have further details: https://communities.vmware.com/message/2877617#2877617
Per our internal testing, the performance issue has been greatly improved. If you experienced performance issue with macOS 10.14.6, pls upgrade to this build and let us know if it works for you.
Thank you for your patience! We appreciate all of you working together with us to understand the root cause and figuring out the solution!
VMware Fusion Team