Gosh, so sorry to hear. I had an initial bout of imbalance and nausea lasting 5 weeks, then it disappeared and I thought I was clear, then it came back with a vengeance 5 months later and added auditory symptoms (slight HF hearing loss, tinnitus) and its taken me 1.5 years for the dizziness to improve again, but I still have nasty tinnitus that fluctuates from barely a problem to annoying. My neuro tells me that can go too eventually and I no longer feel a slave to the condition.
I have a theory that if its fluid disruption/debris/bubbles in your inner ear this can 'hang out' harmlessly in your canals somewhere only to one day return to one of your sense areas and start causing symptoms again.
Did you go med free for a while? Do you recall anything that happened that might have brought in back? Increase in stress levels?
On the plus side be thankful for the good days and all the fun you had in Ibiza. I'm sure there is every chance it will go again. Meantime back on the Nort? (try it on its own first?)