Hi..Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
First of all being HIV positive doesn't cause any symptom like loss of appetite, nausea
. The symptom appear when a HIV positive person gets progressed to AIDS
(acquired immuno-deficency syndrome) & this take months to year to progress to this stage. These symptoms may be related to stress
of having sex with HIV positive person.
Chance of HIV transmission through anal sex from a HIV positive individual is very high, but not 100%. You should first do a HIV test
, it is easy.
If it comes negative then you need not to worry
Even if it comes positive, there are medicines available to delay the progression to AIDS.
Hope this information helps