I can't say much about your sore armpits, but the lymph node inflammation associated with ARS generally involves several areas of the body, such as neck and groin in addition to armpits.
Equally important, HIV
is uncommon in
and women in
all western/industrialized countries, including Germany, assuming no injection drug use, sex with men, immigrants from higher risk countries, and so on. Finally, even if the guy had HIV, oral sex is an inefficient HIV transmission route.