Nausea was one of the most frequent side effects I had while taking anti-epileptic drugs growing up. I'm glad that your seizure didn't turn into one you didn't want to be seen in front of your peers, the black spots again is a potential side effect of drugs, so it may well be worth speaking to your specialist about what you've been experiencing.
Going forward though re your other comment, while I've had a grand-mal in front of colleagues on 2 occasions at work, I wanted to show that how I dealt with them, not only showed my metal, but how insignificant epilepsy can be in someone's life. I simply asked if I could lay down somewhere for an hour or so and made sure I got some food in me. I didn't go home sick as my manager expected and I think my team learnt quite a bit about epilepsy from the first seizure in particular, into the bargain. I guess my point regarding what your seizure could have caused, is only humiliation if you let it. People get sick every day and it's why I'm so desperate to do my own bit to spread awareness, but then if every 1 in 100 people do their bit too and so do their families, we can demolish the stigma.

Katie made some great points about it being side affects. Were you put on a new medication or maybe your meds levels were increased? You may want to bring this up to your Dr. When you notice your dizzy feeling and the smell of cat urine, you may want to get yourself in a safe place . Sounds like your having an aura . Once your in the safe spot , you will have a less chance of getting hurt when you seizure comes around.