Oral sex is an inefficient way to transmit STDs. Of the bacterial STDs only gonorrhea and nongonococcal urethritis (NGU) are transmitted through oral sex; chlamydia is not. If you had gotten gonorrhea or NGU you would have most likely developed symptoms of urethritis (penile infection). Gonorrhea can also be acquired by giving oral sex but this too is quite rare. Even if your partner had an STD (any STD and it is likely she did not), most exposures do not lead to infection.
As for your specific questions regarding oral gonorrhea-
1. Most oral gonorrhea (GC) is asymptomatic and is detected only by testing. the proper test for oral GC is a swab culture taken from the throat.
Oral GC would not be detected by a urine test.
I agree that your symptoms are most likely due to a combination of guilt and anxiety. When present, many oral gonorrhea infections do go away without treatment. When we know it is present however, the preferred treatment is a single injection of ceftriaxone.
Hope this helps. Take care. EWH