Thanks for your question and your condience in this forum.
Some questions can be answered based entirely on the information in the title. STDs are not transnmitted by mutual masturbation, fingering, or any other sort of hand-genital contact. It could theoretically occur and perhaps rarely does -- but with rare exceptions, such exposures can be entirely ignored.
Now I have read the question itself. Guess what? This event has even lower risk that I assumed from the title. For sure there was no risk for chlamydia, gonorrhea, HIV, or hepatitis. There could be theoretical risks for HPV and HSV, but in my 40 years in the STD business, I have never seen a patient even with these STDs acquired by this sort of contact.
I'm a bit confused by your treatment with ceftriaxone for "an infection". That's an unusual treatment in a single dose. Please clarify.
As for your symptoms, no STD causes the sorts of things you describe. They are most typical of phyisical manifestations of anxiety.
In any case, you don't need testing for any STD and I recommend against further self-treatment with azithromycin (Zpak) or any other antibiotic. You should continue unprotected sex with your wife; she is not at risk. (That's what I would do if I were in your circumstance.)
Below I have linked 2 threads with more information on the biology of STD transmission, which further explains why this event carried no signficiant risk.
I hope this has helped. Best wishes-- HHH, MD