I THOUGHT THIS SITE WAS SUPPOSED TO BE UNCENSORED.

It pretty much is. You were flagged by one lower-level user that just happened to be a little higher level than you. Your post wasn't deleted, just "hidden" until more users upvote it. But it's not actually hidden. It just takes an extra click to view it.

And yes, the NSFW tag doesn't work right when it's the primary tag. Just put "NSFW" in your title and everything should be fine.

For the record: Porn isn't something that has been prevalent here, so you're going to encounter resistance from other users. It should be expected, even if this is a "censorship-free" platform. Just remember that nothing gets deleted unless you delete it yourself.