Welcome to the Forum.  Your post was cut off when you exceeded the character limit specified in the introductory section of this Forum.  The encounter your describe was low risk (few STIs are transmitted through receipt of oral sex), you have now been examined by two trained professionals who saw no reason for concern about STI, and in my opinion, without the benefit of being able to examine you, the rash and other symptoms you describe do not raise any concern for STIs for me either. 

It sounds like you may have already had sex with your wife over a month ago.  If so, further abstinence makes little sense to me, given your multiple negative tests and the absence of symptoms. Testing for ureaplasma is not advisable since there are conflicting data about this organism's role as an STI and most experts feel it is simply an organism which is normally present in the genital tract.  As for trich, this too is unlikely and I see no reason for testing in your situation.  As Ai consider your symptoms however, I do wonder just how frequently you are examining yourself- it is not at all unusual for repeated self-examination to lead to local irritation which might cause for the rash and the possible irritation of the tip of your penis. 

My advice- try to work through your guild, stop testing and self examination and try to move forward.  EWH