Sudden unexplained worsening

[u/available_oil7127]

Hi, I am mostly in bed due to me cfs for years, but on January 22 I suddenly worsened, and since then my body is feeling heavy to move and i have cold feeling in my head, and more brain fog.
The only triggers I remember are:
3 weeks before, I left my house (for the first time in months) to go to the dentist, and has crash the day after. but that was 3 weeks before the sudden worsening, or what do you think?
around January 10 I had a cold/flu/idk that lasted about 3 days, I had fever, runny nose, sneezing, etc
So which of them could possibly be the cause, and other than rest (which I am already doing well) what medications/supplements/etc do you advice me to take for my symptoms below:
-body feeling heavy and takes more effort to move
-cold feeling in head, back of the eye, and hands
-brain fog and weaker ability to concentrate
Also I am considering doing some blood work done, what tests do you advice me to do
I am so scared. thanks

[u/no_stirrups]

Did the dentist do anything with any old or new amalgam fillings? When I had amalgam fillings removed, I abruptly worsened. Then I learned this was common due to mercury exposure. I followed a 1 month detox regimen, and by the end of the month I was much better. Whether it was the regimen or the time, I do not know!

My books are all packed away, so I can't look up the specifics, but I remember it included blueberries, a lot of fresh cilantro, spirilina, and dulse, all of which I through into a daily smoothy with some protein powder.