Read Love Is An Illusion Manhwa:
Hye-sung spent his entire life believing he was an Alpha, the jackpot of the genetic lottery. But his world is flipped upside down when he finds out he isn’t an Alpha, but a lowly Omega. This revelation is pushed to its limits when when he constantly crosses paths with Dojin, an Alpha who can’t stand Omegas. Take a step into the omegaverse and find out what it is that makes their pulses race more.. and their bodies go wild.