[Trappped]

This hand came up on Poker Stars nightly 55 k. I was cruising with above average chips (20k av.)with 35k, about 180 left, 153 pays, blinds 500/1000/100. I was UTG and delt KK. I raise to 4000, seat 2 with approx. 30k goes all in, everyone folds back to me. After thinking for about 30 sec., I rule out AA since most everyone wouldve just min raised to clear everyone else out and go HU with me. So now that leaves any other pair and AK, so I call. Seat 2 shows AK and flops gin with an ace and I'm crippled. Now I am struggling that I made the right call for this hand, but was it the right call in the overall scheme of things for tournament poker with my stack and standing in the tourney ? I am strongly leaning towards that I made a Bad Call, since I could've easily folded and still been more than fine. I am trying to improve my game more towards playing flops and less and less and away from "racing" and all-in pre flop. Am I being too hard on myself ? Am I basing this too much on results oriented thinking here ? Or was I a donk and should've insta folded Kings preflop ?