Sorry to hear about this problem. Normally updates simply keep your same data. Did your Firefox mention either:
- the need to create a new profile
- the suggestion to perform a Refresh, sometimes called a tune-up
Either of those preserves your old data, but in different places with different recovery methods.
For personal assistance, I suggest posting this problem on the Mozilla Support site. They have a team of support volunteers to troubleshoot malfunctions with your currently installed version of Firefox, while this site is focused on idea submissions for future versions of Firefox (looking ahead anywhere from 8 weeks to many months). Here's a link to the new question form (for Windows/Mac/Linux): https://mzl.la/3y1vQUQ
