The problem with that argument is obvious, or atleast should be. Same sex marriage was decided on the equal protect under the law clause and due process clause of the 14th Amendment . Simply put, gay people were not afforded equal protection under the law because marriage for heterosexual couples was treated as a right while gays were denied that opportunity. In short it was discrimination. Gays were denied due process until the federal courts interviened.
Guns are not a 14 amendment issue because, unlike same sex marriage, a law limiting where and how you can carry a gun applies equally to everyone. There is no discrimination or issue of unequal protection under the law. In addition, gun advocates have had ample access to due process in the courts at all levels. The courts and law makers must ballance public safet against the vague meaning of the second Amendment which says nothing about the right to bring a gun accross state lines.
In conclusion, yiu have fallen back on a false equivalency logical fallacy rather than actually arguing you point on its merits.