Have you already posted on the HIV Prevention Forum and had your risk assessed by the pros?
There's not much we can tell you until we know if you even HAD a risk.
I can tell you the three ways that HIV CAN be transmitted and if you are not in any of these categories, then you can rest assured you did not have a risk.
1) UNPROTECTED INSERTIVE ANAL/VAGINAL SEX
2) SHARING DRUG WORKS (NEEDLES)
3) MOTHER TO UNBORN CHILD
If none of these apply to you, then you've possibly gotten a nasty flu type bug causing your stomach, diarrhea and headache issues. Normal temp for most people is 98.6, so unless your temp is normally low, you've not had a fever. Severe anxiety over a prolonged period of time can cause many of the symptoms you've described.
I'd advise a visit to your doctor to rule out a physical cause for these symptoms and also a visit to our HIV Anxiety Group to help you deal with the anxiety. Here is the link:
http://www.medhelp.org/forums/HIV-Anxiety-Support/show/595
Peace
Greenlydia