It's more of a rant than a structured argument. I guess my main points are:

1. The only alternative to consciousness arising from some unknown and unknowable process is it being some unknown process.

2. Since you don't know what consciousness is, you still have no more evidence that you're actually conscious than you would if it was unknowable.

Also, the p-zombie argument isn't just that we don't see how lack of consciousness would lead to a contradiction. It's that it's totally unrelated to anything else. There is no axiom you can use to conclude something is conscious without already knowing what's conscious. It's similar to the is-ought problem.