Welcome to the Forum. The risk of the exposure you describe is low. Here are the facts, no matter how many prior sex partners your partner had, the likelihood that she had HSV is less than 50% ( only about 46% of persons with more than 50 sex partners have HSV-2). Furthermore, most exposures to sex partners with HSV do not result in transmission of infection and the risk is even lower if she did not have lesions and you do not mention that she did so it is unlikely that there were lesions on either her mouth or genitals which were not noticed. Finally, your vaginal exposure was condom protected and condoms reduce risk of getting HSV, independent of all of the other factors just mentioned, by about 30-50%. Putting all of this together your risk from this exposure is low.
As for your symptoms and concern about symptoms, the symptoms of newly acuired HSV typically appear between 4 and 10 days following exposure so your earlier symptoms are more likely an indicator of your increased vigilance than anything else. Sometimes after an exposure that, in retrospect, one wishes they had not had, persons tend to examine themselves and be far more attuned to genital sensations than in periods when they are not concerned. This in turns leads to noticing what turn out to be normal sensations that might have been not noticed or ignored at other times. I suspect this was a contributor to your situation. ,
Finally, a question. On one hand you indicate that you are concerned about getting STDs and particularly HSV. On the other hand, you use the internet to arrange for casual sex with an unknown partner. I don’t mean to be intrusive but seems to me that there is a serious disconnect here. I would suggest you reflect on this.
Hope these comments are helpful. EWH