That was certainly the Supreme Court's interpretation in DC v. Heller, but that doesn't mean that historically, all Justices would have agreed with that interpretation. Warren Burger certainly wouldn't have when he wrote "At the time of the Bill of Rights, people were apprehensive about the new national government presented to them, and this helps explain the language and purpose of the Second Amendment. It guarantees, "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed." The need for a State militia was the predicate of the "right" guarantee, so as to protect the security of the State. Today, of course, the State militia serves a different purpose. A huge national defense establishment has assumed the role of the militia of 200 years ago". With the repeal of Roe v. Wade, we saw how the makeup of the Supreme Court can drastically alter its interpretation of the Constitution. We may, in time, see a Supreme Court that is willing to adopt a collective rights interpretation of the Second Amendment more in line with the Court's previous ruling in United States v. Miller.
As to your sex amendment example, I think it is more than likely that the current Supreme Court would interpret that amendment to mean that an individual's right to have sex was predicated on their intent to reproduce rather than any unfettered right to have sex. They certainly wouldn't interpret it to mean that sex between same-sex partners was an individual right guaranteed under the Constitution.