Good that you are back Skarpi, but sorry to hear about your Mum and your friend.
We also visited Iceland 2 years ago on a cruise, but we had several land-based excursions to many interesting places:geysers, waterfalls, the ancient parliament, the place where the tectonic plates meet/divide . So many people asked us if we saw the Northern Lights, but it was midsummer, with very little darkness!