However, this headache was not a typical headache. I felt tingles in my head and it felt like my brain was expanding and putting a lot of pressure on my head. Sometimes it would cause me to go into a state of panic and I felt paralyzed with fear.
I think it more probable just a fairly normal antidepressant headache plus some extra symptoms triggered by fear. While headache can be a symptom of serotonin syndrome, it is not usually the only one. The other common symptoms are agitation, confusion, diarrhea, dilated pupils, loss of muscle coordination and/or twitching muscles, rapid heart rate with high BP, severe sweating and shivering.
While care needs to be taken with SSRI and some other serotonergic ADs with Adderal, Effexor is fairly mild in that regard. Plus true serotonin ir probably a much rarer condition than the popular literature suggests.
I'm not a fan of polypharmacy prescribing. The fewer number of drugs the better, IMHO. You are on a lot of drugs and seemingly going backwards at an accelerating rate. Frankly I find your entire medication regime odd and suspect at least some of your problems result from it.
In addition to my disquiet about the Haldol, which we've discussed previously, I wonder if you really need to be taking both Ambien and trazodone, and I also wonder whether Adderall might be a significant driver of your insomnia, and perhaps also the chanting. I suspect you might be far better off with just one of the two ADs proven to be most effective for OCD, Luvox (fluvoxamine) or Anafranil (clomipramine) plus some therapy and, if necessary, maybe a mild mood stabilizer. I really think you should get a second opinion from a psychiatrist if possible.