Bex
Good decision well made. I flew down to the South Coast lunchtime and the vis was pretty poor so as another ATCO / Pilot I can only applaud your decision.
Without an IMC it would have been very tough going - as it was I was going into a big airport (albeit ILS unavailable) in a well equipped twin. The runway was still hard to see until you were almost on top of it. (Approach lights would have been a help - they might have been technically CAVOK but it wasn't what I would call CAVOK!).
You made the right choice - hopefully others will learn from your posting that there are times when you have to say no.