Yes, you could have contracted this more than 25 years ago and the area on your labia that gets tender could most certainly be herpes.
Daily therapy with acyclovir or valacyclovir can reduce transmission rates to a partner by about half. I would be cautious about other topical medicines. we know, for examples, that nonoxynol 9, a antiviral agent found in some condoms and vaginal, can actually make the situation with transmitting herpes worse. So be cautious. I would stick to stuff that is known to work, like these oral antiviral agents.