Folding Pocket Kings to ALL-IN bet on scattered flop with 2 diamonds

Here I raise with black Kings after several limpers to table standard plus limpers.  I am in the Lojack and get calls from cutoff and button.  The flop comes 10 6 3 with two diamonds.  I bet out $115 about 2/3 pot and get raised all-in for another $240.  This is a rather large bet and its possible that my opponent has pocket 10s, pocket 6s or pocket 3s in their range for a set or they could have a diamond draw and has 9 outs. I folded figuring I would be in big trouble if he had a set and not that much of a favor to something like a pair and flush draw.  Was this the right decision and how would you analyze this situation. Thanks much for your feedback. Gil