No, dear boy, your argument is BS. Like all Protestants you try to solve the issue by taking a single verse out of context of the whole Bible.
The facts are that Paul ministered to both Gentiles and Jews, witness the references throughout the New Testament of his teaching in synagogues, as well as his having his disciple Timothy circumsized to placate the Jews he would be working with (or did you just conveniently "forget" those facts).
Obviously, Peter did the same, since he was the one who started the ministry to the Gentiles in the first place.
Well surely then you can explain what the context of these verses is...
Gal 2:7 But contrariwise, when they saw that the gospel of the uncircumcision was committed unto me, as the gospel of the circumcision was unto Peter;
Gal 2:8 (For he that wrought effectually in Peter to the apostleship of the circumcision, the same was mighty in me toward the Gentiles:)