I think a fold here is reasonable. If we assume that he moves in with all of: AA, KK, QQ, JJ, AJ (s or o), or 66, you are 40.4% to win. According to my calculations, calling the rest of his stack, you would need just over 40.2%. Technically, it would be minisculely +EV to call, but folding as you played it is correct.

I do like the line, and I too would probably fold. You asked for and received information. You processed it, and made a valid decision.

I think you played it very well.