Federal courts rewriting state laws or creating whole new state laws is unconstitutional. That is reality.
We've lost the country as a whole. Even among Republicans, there is a disturbing percentage who favor allowing gay marriage. Which of the states now allowing it will reverse course? Which court case, if it goes to SCOTUS, will result in our favor?
All of that means that yes, we have largely lost the war over gay marriage. To admit it is not a "slippery slope", it's reality. And unless we want to start losing any of the other battles you mention, we will need to start acknowledging reality.
I can understand why you feel that way, living in California. I used to live there, too, and its depressing as hell because it's like living in a sensory deprivation chamber. But that chamber -- where everyone is repeating the same thing whether you overhear them at the coffee shop or hear it on the news or in the movies you watch -- is not how it is in the rest of the country. It's like that old Saul Alinsky technique of placing 4 people in a diamond pattern within a crowd and getting those 4 people to get up and speak their script...and soon, everyone in the crowd thinks, "Wow...everyone must think like that! Maybe I should keep quiet, because I'm surrounded!" No, it's only 4 people with pre-written scripts in a crowd of 100. But now they've got you questioning yourself.
Consider what you just wrote there: Which court case, if it goes to SCOTUS, will result in our favor? and ask yourself this: Did the Founders EVER intend for 9 court justices to possess that sort of absolute power? Did the Founders intend for corrupt politicians to remain in their offices until they were over 100 years old and propped up by assistants (read: puppet masters) to sign bills that they cant even see, much less comprehend? No.
So I say that we have not lost the people (although coastal California is lost. It is beyond lost.), but we have lost the government. And there are only two remedies to turn things around. 1) Civil War, which no one recommends because just. No. (and some would say that is exactly what they want) or 2) Article V of the Constitution: The Congress, whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution (yeah, right, as if Congress would ever want to abolish its current abuses of power), or, on the Application of the Legislatures of two thirds of the several States, shall call a Convention for proposing Amendments, which, in either Case, shall be valid to all Intents and Purposes, as Part of this Constitution, when ratified by the Legislatures of three fourths of the several States, or by Conventions of three fourths thereof, as the one or the other Mode of Ratification may be proposed by Congress This process has been spelled out in Mark Levins Liberty Amendments and it has already been put into motion.
What is there to gain by continuing to vote for people who tell you one thing and then get into office and turn their coats; or when you finally do get a good one (Reagan) and he puts his guy on the Supreme Court, then THAT guy turns his coat... it's like banging your head against a wall. The only solution is to take the power back from the Federal Leviathan and give it back to the States, as originally intended.
Or there's that Civil War option. Which would you rather try?