@eranshefi no doubt w3tc is very good plugin..if you have same issue after deactivate w3tc plugin then you have to delete w3tc folder and w3tc related files manually via ftp. now if you want back again website speed fast and want to use w3tc then clear all cache of your browser and reload Browser and try again to install w3tc and config it correctly.
i had same issue but i want w3tc as a cache plugin. so i do same above steps now i dont have any problem related w3tc.