I use TB all the time, both 32 and 64 bit
I have no problems, freezes or even hesitations.
As far as the problem is concerned.
Backup your emails.
Can be done by installing an add-on, called:ImportExportTools 2.7.2.2
This will allow you to :backup-save in text-html-eml-cvs.....single-folders-groups
Then wipe of TB from your computer, including .thunderbird
Reinstall all
reinstall addons you really need
Import mail folders again
If you still have a problem....I will resign from my post as useless-info-agant.