I got a full-panel check of STDs one year ago (I didn't do HSV-1 antibody tho)results were all negative. Since that, I had unprotected sex with my ex-girlfriend(last time was 4 months ago). I visited CSWs 3 times in total and I have Unprotected Oral sex with one of them for 2 minutes 4 MONTHS AGO. All other sex were condom-protected and I checked the condoms every time after the sex. Last time I visited the CSW was exactly one and half month ago in U.S and everything was protected.
Since I clean and examine my penis everyday, I am very sure no symptoms showed until TWO WEEKS ago:
I met my current girlfriend 3 months ago who said she never had unprotected virginal sex with others before and she also got checked. We had unprotected oral and virginal sex several times. Two weeks ago, I saw some red rash on my glans with itching which disappeared in 3 days while I saw some white dry secretion from my penis skin instead of from the urethral opening. I thought it was fungi and applied anti-fungi cream, everything went well but then I saw an ulcer on my frenulum of prepuce. (I always have a CUT on it after sex). Also a small tiny red blister on the coronary sulcus. 2 days after, another 3 blisters on coronary sulcus appeared then and the ulcer was still here, also I was having swollen lymph nodes and painful urination, which make me believe that I have the genital herpes. I went to the clinic and got the swab test and the result was HSV-1 positive and HSV-2 negative. The symptoms have been there for 2 weeks even after I took the Valtrex, which again suggested it should be my first outbreak.
I told my girlfriend to check but her results were all negative. (She showed no symptoms at all so the test method must not be swab tests).
I am very confused now since last time I had unprotected oral sex with a girl other than her was 4 months ago and I believe the protected oral sex with CSW one and half month ago was very brief ( less than 1 minute). I don't really now how I contacted the virus if my girlfriend doesn't have it. I know HSV-1 GH is much less infectious but I still don't want to put her at any risk.
So what is the possibility that how I got the HSV-1 and is there anything I could do now?