Sometimes the "sudden" instalation of symptoms could be because of the "drop" that filled the bucket IMO. the last dose of whatever could be that drop even you didnt feel something before. Hipothesis
For me the following things provoked "sudden" simptoms: Amalgam removal, too much too soon detox, burden liver, sudden aquired infection GI and lungs, major stress. BUT pre existing factors had their role obviously. Methylation and histamine issues due to already chronic infections and genetics plus (my guess) long time leaky amalgams.
I know that supplementing for methylation is tricky so you need to monitor your reactions.