John, your anxiety about the potential consequences of the one-night stand (while valid) seem to be misleading your thoughts as to the cause of your ill-health.
First of all, HIV does not typically cause illness immediately. There is usually a symptom free period of several years before it finally comes up with a mutation which overcomes the immune system. Unless you already have pretty severe immune system failure due to (say), Hepatitis, then it is astronomically unlikely that full blown AIDS has pounced upon you overnight, causing symptoms that rapidly. It would be sufficiently rare to create newpaper headlines around the globe, and have you comprehensively studied by world famous medical researchers.
Secondly, AIDS would typically although not always present itself with the first symptoms being Karposi's Sarcoma (a rare form of skin cancer - black blotches) and frequent fungal and microbial infections. When I say frequent, usually they are one after the other, with little or no respite. This is very much a hallmark of AIDS; as the immune system collapses, more and more pathogens are able to overcome the damaged immune response.
So, perhaps it would pay you to consider other potential vectors of disease. For example, guardia from infected water. (I haven't the faintest idea what the risk of this would be - it might not even be possible in Mexico - I use it merely as an example of water-borne diseases.) Also, parasitic infection from food.
What you describe seems to include fever, bloating, and possible knock-on effects due to a prior infection with EBV. Unfortunately I cannot comment on your BUN and CO2 test results as I am not a healthcare provider and don't know these tests, but I do wonder if you have been tested for Hepatitis ? The reason I ask this is your mention of pain around what may be the liver region, followed by a severe immune reaction which has persisted. Also I believe fever may be associated with the sort of infectious agents that may cause viral hepatitis.
Please note that my reasoning as regards potential alternative causes for your ill-health may be erroneous due to lack of knowledge. However I have followed the body of scientific research on AIDS literally since day one, ever since its' symptoms were first mentioned as a medical curiousity, long before it was understood, so I am confident that what I say as regards HIV is correct and up to date. Research on HIV and AIDS is still very high profile.
My ( amateur!) advice would be to go back to your Primary Care Provider, with a clearly written timeline of past medical health, plus of all the unusual things your body has been doing since Mexico. This includes any minor changes in appearance (eg fingernails, skin tone, eyes, hair) that seem to be persistent. (Keep a copy for yourself, keep updating it as necessary. Good idea in any case.)
As regards looking up information on the internet, perhaps About.com might have a forum on hepatitis that would help allay those fears. Apart from that, try all the usual Search engines - you will undoubtedly find more information than you know what to do with !
If you are concerned about your health, and seeing medical professionals who seem off-hand or unconcerned, or are not listening, I would suggest you vote with your feet. Given a half million years of evolutionary pressure (your body's warning system) versus a doctor's handful of years in training, in any case of disagreement I'd go with what my body is telling me every time.
Hope this helps. (I won't give you a list of "don'ts", I'm sure you have learned that lesson. Here's hoping this is an ultimately harmless boost up that learning curve called Life, that we are all on ! )