What puts your partners into a "high risk" group?
In any case, performing oral on a penis (or penises) does put you at risk for a couple of things, but none that would give you the symptoms you have.
Giving oral sex to someone with a penis puts you at risk for oral gonorrhea and syphilis.
Oral gonorrhea doesn't often have symptoms, but the most common is a sore throat. You can test for that with a throat culture about 5 days after exposure.
Your partner would have had to have a sore on their penis to transmit it. You wouldn't see symptoms of this for 10-90 days, but the average is 21 days, and you'd get a sore called a chancre. Since you gave oral, you'd get the sore in your mouth. You can test for this at 6 weeks. If you get symptoms, but test negative at 6 weeks, test again at 90 days, and get to the doctor as soon as you see symptoms.
Syphilis isn't common in a lot of places. I don't know where you traveled, and don't need to know, but it's not nearly as common as chlamydia, for example.
Perhaps while traveling, you picked up something - norovirus, a parasite, any number of stomach viruses - the list is long and varied. Maybe the foods you were eating didn't agree with you. Since you're home (it sounds like) and you're having the symptoms again, you should see your doctor. Maybe you have a food sensitivity, or have issues digesting certain kinds of foods, like those high in fiber, etc.
HIV is not a risk, so you don't need to test again. I don't know where you live, but most places in the US, Canada, the UK, etc., have organizations that offer low cost or free HIV testing should that ever be a need for you in the future. Google "free HIV testing and your location" to find it. You don't need it now, though - just wanted to let you know.