>found out during a routine check-up last year that included broad blood work that I don't have any Mumps or Measles titres
Must you must have one hellovah health plan if your "routine check-up" includes that level or analysis.
If any of this is true (and it's not simply slide bait) them it's more likely the result of breathing smoke than from monkeying with neurotransmitters. You get mostly the same products of incomplete combustion regardless of the species of plant is being burned.
>Only time I’ve really been “sick” is when I have to travel and can’t get weed!
When you can't get weed is the only time you notice that you're sick.