Tac, have you forgotten that Orochimaru's entire goal was not just the Sharingan but the entire body of the Uchiha that goes along with the eye?
Orochimaru had plenty of connections to get some spare Sharingan from Danzo for instance. The entire point was to take an Uchiha's body. Orochimaru recklessly attacked Itachi and burned his hand by being struck with the vast difference in power. That was the one Uchiha directly in his reach yet he completely abandoned that option to groom his younger brother and dive into years of stress to put up with Sasuke's bs. He literally complained himself that all this is only because Itachi is way out of his reach.
Lol why are you going into this drivel.
Yes, Orochimaru wants the sharingan and the only ones who can unlock the true power of a sharingan is an Uchiha.
Orochimaru still had options when he was defeated by Itachi—his goal of gaining the sharingan was not lost, ergo he did not lose any will or lack willpower to achieve it. Itachi was one of multiple avenues to obtain it, so Orochimaru's ambition shifted over to Sasuke, because these individuals do not matter besides their potential (and as it turns out, Orochimaru confirms Sasuke has greater potential than Itachi in their first encounter).