There are several options. Online manga platforms such as KissManga or Manganelo might have it. Or you could check out dedicated manga apps available on your device's app store. Just make sure they are legal and reliable sources.
You might try some popular manga reading platforms like MangaFox or MangaReader. They often have a wide range of manga available, including 'Can't Think Straight'.
It's a story about two characters struggling with their feelings and identities in a complex world. There are lots of twists and turns that keep you engaged.