Fast food is dry from frying and contains a whole lot of MSG. That causes dehydration and thick blood.
Fish oil/ Omega 3 fatty acid is shown to decrease inflammation.
It sounds like you suspect that meal triggered the symptoms. I'm not saying to seek medical advice or not. I'm not offering advice.
Just saying that I have decreased inflammation, stress and thinned my blood with fish oil, magnesium and lots of water.
There are many other things I've done, but your needs may vary.
Stress is another thing that you mentioned. That uses up nutrients in the body faster than most anything.
I just recently was sent a short video from one of my teachers, the honorable Dr Jennifer Daniels. Maybe this will encourage you about the other challenge some.
More Powerful than Even a Superfood