CC2018 slow importing & keeps crashing down

This is so annoying. Import a normal file would take several minutes, timeline lagging occasionally, and the project keeps crashing down every few hours.

How could I solve this? I've cleaned cache and even restarted computer several times.

Very disappointed at the upgrade! I use Mac Pro 2013 and never had any problem in CC 2017.

wish could go back to 2017 but apparently most of my recent projects have become a newer version and cannot opened in CC2017, even the auto-saved files before I upgraded to 2018... And I guess there's no way I could down-convert the project files?

Thank you all if anyone could help me with this!