TabSearch does the same thing you're doing with the search bar, but with fuzzy searching and more customisability which makes finding tabs a bit easier.
Close Discarded Tabs is a very simple extension I wrote for myself that acts as a sort of garbage collector for Auto Tab Discard. You can customize Auto Tab Discard to discard tabs in a way that purges irrelevant tabs to your liking, and then if you notice the list of tabs looks a bit overwhelming, just click the trashcan and all the discarded tabs are closed. If you want to make sure you don't close a tab you wanted, just quickly scan through the list and click any that you want to keep.
TabSearch: https://addons.mozilla.org/en-US/firefox/addon/tab_search/
Close Discarded Tabs: https://addons.mozilla.org/en-US/firefox/addon/close-discard...