Autumn

No, he was not with omegas, he spent his rut alone, but Hua Yong doesn't know that and he got very upset and jealous. He thinks because him and Shaoyou can't sleep together yet means Shaoyou is spending his ruts with others even though he hasn't been. That's why Hua Yong purposely overdosed his modifiers (that make him smell like an omega) and why he ended up in the hospital, was to basically get back at Shaoyou, even though Shaoyou didn't do anything wrong, he's just bad at communicating.

Hua Yong is doing all of this to test Shaoyou's love for him and also change the commitment issues and prejudices he has. Wenlang said that Shaoyou would never be with an Omega that's been with an Alpha, by lying about being assaulted Hua Yong is testing Shaoyou's love for him, would he stay with him and love him if he knew that Hua Yong had been with alphas (consensual or not). He's lying about his disorder because Hua Yong, being an Enigma, has to be the one to mark Shaoyou, so he lies about why they can't sleep together until he can tell Shaoyou that he's not actually an Omega, because otherwise Shaoyou would want Hua Yong to be the submissive partner. Also Hua Yong was very weak when he came back from the hotel (which was real because his ruts are very intense) so Shaoyou thinks that's part of his disorder and from being assaulted, and why the doctor told Shaoyou not to have his rut around Hua Yong because Alpha pheromones could hurt an Omega with a pheromone imbalance. Hua Yong fainting was real, though we know it's self inflicted, Shaoyou again thinks it's from his disorder.

yes, ChanJet are the second couple