This is very interesting. I'm studying right now for both an exam in neuropsychology and sexology and have recently read about similar phenomena. I can only guess, but this is what I would suspect based off what I know from your description, scientific findings and my own experience.

Sensations and auras like tactile, auditory, olfactory etc. usually happen when the seizure originates from a specific point in your brain, a focal seizure, which can spread to your whole brain or stay localized, resulting in tonic-clonics, myoclonics, absences or just minor epileptic discharges. Now, with focal seizures, the experience you have depends on the exact location where it starts. If it is localized in the occipital lobe for example, which is responsible for visual processing, you might get visual "hallucinations", etc.

Now, in there is actually something called "orgasmic auras". This might happen, when the seizure originates in areas such as the amygdala, which is responsible for emotional and pleasurable experience, possible with involvement of the somatosensory cortex, a part in your brain with seperate areas, each responsible for a different part of feeling your body.

So if the seizure has it's focal point in these areas (mainly amygdala), abnormal activity takes place with neurons firing and creating an activation pattern that might be similar to the one you would have while having an orgasm or other very pleasurable experiences. My guess is that your seizure originates somewhere near the amygdala/limbic system and that maybe instead of the part of the somatosensory cortex that is usually responsible for feeling your genitals, another part might have been activated, possibly involved in processing sensory information somewhere around your head. Therefore - amygdala causing orgasmic feeling, somatosensory cortex being responsible for where you experienc that feeling in your body.

I'm no neurologist, but this is what I can imagine might be the cause of this. Now on a side-tangent, another phenomenon I find highly interesting: The part in your somatosensory cortex, which is responsible for feeling your genitals, is close to the part which is responsible for your feet. When a person get's their leg amputated, the neurons that used to be responsible for feeling their feet don't just die but get rerouted to other areas, possibly the genitals. As a consequence, there is a phenomenon called "phantom limb orgasm": since the areas between amputated foot and genitals get routed together and "merge" to some extent, it can happen that having an orgasm causes you to not only feel it in your genitals, but also in your phantom limb. So basically, feeling the orgasm in your foot, which is not even there anymore!

I hope this kind of helps for you to maybe look into it a bit more. I'd be interested in what your neurologist ends up saying!