Last week, I had diarrhea too. I'm sure many other members also get it from time to time. It doesn't mean we all have HIV.
You had no risk and you couldn't have infected your wife with something you didn't have in the first place.
And the smell of garlic isn't an indication of HIV, maybe an indication of garlic bread, but not HIV.
The HIV line advised you correctly, you weren't exposed to any risk. The most common symptoms people get when they get HIV are the ones associated to ARS, which usually emerge around 20 days later and include sore throat, fever, and a strong skin rash. What you describe doesn't sound like that at all.
However ARS symptoms are not a reliable way to diagnose a possible HIV infection, the only way to do that is to get tested, but, based in what you describe, you don't need to.
You might try to post your question in the general STDs forum.