I see you have said you are seeing a psychiatrist. Let me sum up some advice for you:
1) The combination of medications can certainly cause what you are feeling. This is especially true when adding/increasing dosages. The combination of the two medications, is sometimes avoided due to the interaction. Some psychiatrists, however, like to give this combination of medication if they believe there is a benefit for the patient.
2)The Effexor dose is above the maximum for PTSD. I would speak to your MD regarding so. Using Effexor above the maxmium along with trazodone , can have bad consequences. Your MD should be very very careful with your drug regimen. I am not an MD, but from a pharmacists stand point, I cringe when I see these combos at high doses.
3) Avoid herbals, such as St John's Wart, as these can increase these symptoms, and toxicities.
4)Never take more/less than what is prescribed unless you speak to an MD first.
Let me know if you have changed any drug doses, or added anything too. The more info you give me, the better equipped I am to help you.