Whats this logical form called?

This is a Non-Sequitur for sure, as well as a fallacy of opposition.

X is the enemy. 

X says Y is true. 

Therefore, the opposite of Y must be the real truth.

In other words:

P1) Person A says X is true

P2) If Person A says X is true, then it is not

C) X is not true

This is a formally valid syllogism, but an unsound form of reasoning - it is a genetic fallacy. Your example follows this logic - because of the origin of the claim (the "enemy"), it is rejected.

Facebook fact checked me, then censored me as being extremist content, therefore what I posted must be the real truth they don't want us to know about. 

This actually seems a bit different. It's still a fallacy though - the appeal to censorship. "I was censored, therefore I am right." It's a non sequitur.

fallacy of opposition