Firefox has become glitchy recently and won't load gmail, etc.

I've always used Firefox as my default browser, it's been updated and is the current version. Recently I have noticed that pages are slow loading and some images on the page never load properly and remain blank. More vexing, is that Gmail has become very unstable in Firefox and won't load properly, loads slowly and freezes blanks out when I try to delete trash or spam, etc. It's annoying as more and more I have to open up Edge Browser to get performance on the websites that are failing in Firefox. This includes various websites that I use for work where logins are glitchy and unstable in Firefox, but work in Edge? Disappointing as I prefer to use Firefox, but even with recent upgrades installed it seems to work less well than in the past.