Fonts missing FCPX 10.4

Today, when I opened a video project that I've been working on for the past few months, I expected it to run smoothly. But then I noticed, ALL fonts have changed to Helvetica.

I'm using FCPX 10.4 on High Sierra (seems to be my biggest mistake last year) with plug-ins from VideoHive. I'm using stock fonts from my macbook pro (mid-2012). But I don't remember which ones I've used. And there are too many, too time consuming, to make manual changes.

Prior to today, I reinstalled High Sierra maybe 7 days ago, because of over heating when the macbook is plugged in the socket. Soon after I installed FCPX 10.4 on the same day.

Today, many days after, all my fonts have changed. Even the backup libraries automatically do the same.

This is the first time this has ever happened to me or to any of my projects. Now font changes are happening to ALL of my FCPX projects.

How do I fix this??