How long have we been infected? Is there any way to know?

I am a 51-year-old male, married for 14 years. I ended an 18 month long affair 2 1/2 years ago. Six months ago, when my wife found out about the affair, she and I were tested for STDs. Sadly, we both tested positive for HSV2. She tells me that her test result was reported at a "level" indicating that she was "recently" exposed. This has subsequently raised her suspicion that I have had extra marital sex since the affair ended 2 1/2 years ago, which is NOT the case. The last time I had anything resembling the classic symptoms of an outbreak was 30 years ago. I had itchy bumps on my penis, which broke, crusted over, and disappeared after 5 or 6 days. I went to a public health clinic where the infected area was swabbed. Test results were negative, but I am not sure for what specific STDs the culture was tested. I had no knowledge of herpes 30 years ago and do not know if I was tested for herpes at that time. Since that time, I have periodically experienced uncomfortable, tingly sensations on my penis that will last for about 1 day, but no blisters or lesions like what I have read about. Knowing what I know now, I suspect that I have had herpes for 30 years and did not know it, and transmitted it to my wife sometime over the last 14 years of our marriage. I want to do anything, everything to save our marriage, and this is a real point of contention for her. So my question is this: Is there a test that can actually determine how long we have been infected? We both want to know.