Were you tested previously and negative? If so, you may well have caught it from your partner, probably by kissing but possibly by oral sex. Say more about your partner's HSV1. Did she have a diagnosis of oral or genital herpes, or just a positive blood test?
Half of all adults in the US (more or less in other countries) have positive blood tests for HSV1. Mostly these are from undiagnosed childhood infections in and around the mouth, often with no symptoms. This might explain both your infection and your partner's. Or you might have been infected from your partner, either by kissing or oral sex, depending on the location of her HSV1 infection.
So could you have caught HSV1 from her? Yes, but not necessarily. And test HSV1 can be spread between anyone having oral-oral, genital-oral, or genital-genital contact, regardless of sex or sexual orientation.
I may have more to say if you want to give more information about your and your partner's diagnosis. In the meantime, this really shouldn't be a big deal. Most likely you have a longstanding oral infection since childhood and are unlikely to infect anyone else.
How have you been diagnosed as having HSV1?
I would suggest thought that it is most likely that you have had HSV1 orally since your youth. As such there was no real chance of further infection between two people who both have HSV1.
There was no real reason why your partner took antivirals (if this is what you mean?) with a HSV1 infection unless her outbreaks were bad and frequent. I assume hers were oral?