A very interesting question! I would hazard such an interpretation: “you” here means not specifically this person, the questioner, but a, so to say, statistical Jew who thinks that the very fact of being a Jew, a member of the chosen nation physically descending from Abraham, is enough for salvation. Since such Jews were majority and, on the contrary, Jews who correctly understood that taking cross and following Christ’s life of purity and perfection to the point of loving even enemies was a sine qua non for salvation, were minority, then truth of His words stays: few will choose to follow Him.
However, when He indicates the many coming from all parts of the world, He does not contradict of course Himself, but says that salvation is for representatives of all nations of the universe, and those chosen from each nation will come to the blissful banquet of salvation, and since nations are many, such chosen ones will also be many, but they will be few of and in each nation, for few are those who choose the path of perfection in Christ and even many of His disciples could not withstand following this path (cf. John 6:66).
Thus, there is not any contradiction and Christ’s prophesy that many will follow an easy path leading to damnation, while few will follow the difficult path of salvation, which prophesy is firmly established both for Jews and for all other nations, for all humanity until the end of history.