While it is possible to infect someone at a new site after they have established infection at another site, it is incredibly rare. I have seen it once in 33 years of practice and heard about it once on another forum. That’s two in 33 years.
We do not have a percent of people who transfer this from genital to genital contact. It has been documented in the literature but I personally have not seen someone with genital HSV 1 who did NOT say that they had received oral sex at their most recent encounter, prior to diagnosis.
About half the population has HSV 1 so it is likely that you will encounter a sex partner who is also infected at some location. It’s a sad thing that you have let this consume your life – I hope you can think about this differently somehow. I have HSV 1 orally and so does my husband and thinking that I might give this to him by giving him oral sex never ever crossed my mind as a worry. Never.