My apologies, I forgot to ask if you’d perhaps tried only the Brain Regeneration field as it is rather gentle.
(perhaps without any other fields, or only strengthening the nervous system and energy system with the Energy Expansion card)
Yes, the nervous system regulates blood sugar and blood pressure.
Both during and following mononucleosis and Covid infections, there can be some damage to the nervous system and endothelial junctions.
Fluctuations in blood sugar and blood pressure in response to lower levels of stimuli are not uncommon when this is the case.
One’s threshold for different input is typically lowered for some time in these cases. Often this can be even more so in the weeks or months afterwards as it is part of the body’s natural processes following the infection.
One might not always notice overwhelm to one’s system immediately and it can take some time to recover if overwhelmed in this case. So it is better to reduce what one is doing and allow one’s system adequate rest.
(whether from too much input from fields or anything else)
Keep in mind that it can take some time to recover and heal following viral infections, depending upon the specific issues in your situation.
That’s rather likely too many fields! 
Particularly if one has mononucleosis and possibly Covid, one should reduce the amount of stimuli and different burdens on one’s system during the infection and recovery necessary afterwards.
Too many different fields can certainly overwhelm your system, particularly at a time when one’s threshold for different input would be lowered.
It is best to allow one’s system to recover and rest adequately in the weeks or months afterwards.
If one has significant energy or health issues, it is often best to limit one’s stack to what one is certain one can handle and observe any signs of overwhelm carefully.
(and often best to first focus on acute issues such as viral infections)
From other discussion threads: