Welcome to the forum.
I can reinforce the accurate reply you had on the community forum. STDs are rarely if ever transmitted by hand-genital contact; and although oral sex carries some risk, this too is virtually zero for the brief contact you describe.
There are no STDs that cause upset stomach, testicular "sagging", or erectile dysfunction. The testicular business undoubtedly isn't abnormal -- there's no medical condition that can cause increased "sagging", and that almost has to be just your perception. All your symptoms are very suggestive of an anxiety reaction, presumably because you regret and may be experiencing overt shame or guilt over your sexual choice.
If I were in your situation, I would relax, not get tested for any STD, and would continue unprotected sex with my wife without the least concern about infecting her with anything.
I hope this has helped. Best wishes--- HHH, MD
Thank you Doctor. I was hoping for that answer. Very much appreciated.