Alana, I wont use fertilizer until the plant has produced new roots. It can take anywhere from 2 weeks to 6 weeks for the pseudobulbs to produce new roots. You can start using fertilizer at very weak strength (>100 ppm) once the new roots are about 2 inches in length and start becoming white.
Also it is normal for Catt leaves to be very hard. There are exceptions though, C. quadricolor leaves are very flexible and can be rolled up, it was once a very common way to distinguish quadricolor from other catt species.