A diet largely consisting of squid doesn't do much for the state of your digestive system or your breath, you really don't want to be breathed on by an elephant seal. Most of the time pods are quite fairly restful places in a constant snoring and guttural grumbling sort of way, but every now and then one of the inner most seals decides it wants to go to sea.
I have never had the severe symptoms you describe after a cleaning, that's quite a reaction, but have felt very tired. I chalked it up to emotional exhaustion as I hate having my teeth cleaned. I agree with Wayne Mikie, it feels good to see your name. Hope you are feeling better.
ANY type of bad infection could cause all kinds of bad-ness throughout your system. It can spread to your brain and kill you. Now go see your Dentist. Yes. Yes! The infection from an abscessed tooth can cause all sorts of trouble, including heart failure, if left untreated. It can cause you to have a very toxic system and you will die of complete system poisoning through your blood. It's really foul. Cowboy up and have the root canal, please!