in your case, I was mentioning heavy metals a little tentatively, but your response to my suggestion is intriguing.
I've been having another conversation about heavy metals in another thread, where the symptoms seem (relatively) clearer in suspecting heavy metals.
Before we go any further, perhaps you'd consider perusing that thread and let me know (here in your thread) if any of it resonates with you. It may not, of course...
I'm asking you to read that thread first because in it, I describe how I faced a predicament just as you've described - namely the inner question "how is it possible?"
Well, you say you had Amalgams removed some years ago. As you may or may not be aware, when Amalgams are removed there is a very real risk that vapour may be released in quantities significant enough to intoxicate the patient (properly done, Amalgam removals involve provision of a seperate oxygen supply for the patient, along with use of a dental dam to prevent passage of mercury down the throat. EVEN THEN, intoxication of the patient, to varying degrees, is rather common. Mercury is extremely pernicious stuff). If you wish, we can get into this in a bit more detail, but I won't go further in this reply, at this early stage.
I had Hep-B vaccinations (containing ethlymercury preservative) several years ago and my decline in health did not occur suddenly - it has continually evolved over a period of almost a decade. I do now understand how this is possible but it bewildered me for a number of years.
Let me know your impressions and, whether or not it resonates with you, we can perhaps bounce around a few more ideas about your situation. As far as the metals side of things goes, I don't have any knowledge on 'Kawasaki', but if the above metals discussion resonates strongly with you, as an adult, I'll be most happy to help you navigate through the hows and whys and ways to move forwards, but there's much to read in the above thread which may answer some of your questions on the topic.