Context for lines: https://magiarecord-en.com/comic/18.html
https://gamepress.gg/magiarecord/manga/magiareport-s1-episode-29 

https://gamepress.gg/magiarecord/manga/magiareport-s1-episode-28

Sayaka is a bit tomboyish and acts heroic. She is devoted to her friends, especially when she makes the contract right away and saves Madoka. She has a large girlish side in that she loves classical music, and is very interested in romance. Sayaka seems to have had an extremely black-and-white and idealistic vision of love, which seems to have contributed to her breakdown. After learning the truth about the Magical Girl contract, she felt that she could no longer approach him, and this wasn't helped by Kamijou's obliviousness to her feelings and Hitomi's more assertive behavior that ended up with Hitomi becoming Kamijou's girlfriend, unaware of Sayaka's problem. This is why she falls into deep despair, a self-destructive spiral in which she refused help from others (especially Kyoko, Homura and Madoka), seeking to either die or kill to dull the pain. As a result, her soul gem became corrupted and ultimately caused her to become a witch. When she listens to Kyosuke one last time, she actually feels glad and proud for him that Hitomi will make him happy.