Orwell wrote 1984 after beeing delusional on how the communists behaved during the Spanish civil war, where he inititially fought for the communists.
Orwell never fought for the actual Communists (i.e. the Russian aligned Communist Party), he fought for the POUM (which was a Trotskyist group). The exigencies of Russian foreign policy (Stalin wanted an anti-fascist alliance with Britain and France) caused the Communists to be the conservatives on the Republican side. For example, everywhere the Communists (as opposed to various Trotskyist and Anarchist groupings) gained control, factories which had spontaneously been "collectivised" by their work force were returned to the hands of the prior private owners.
The musn't upset bourgeois Britain and France line (the vanity of which reached it's denouement at the Munich conference) being pursued, at Stalin's behest, by the Communists in Spain was natural perceived by more radical leftists as a gross betrayal. Orwell saw it as such. Orwell too perceived the danger of the requirements of State taking precedence over the liberation of workers. I'm not sure how you think he was being "delusional?!" Disillusioned perhaps, but then he obviously didn't hold the Communists in high enough regard to fight with them in the first place.
I recommend reading his Homage to Catalonia, not only because it clarifies the meaning of works such as Animal Farm and 1984, but because it's a damn good read.