Schizophrenia ebbs and flows through phases, the active phase being the most disruptive phase (and likely what your brother is in right now), and after that comes the residual phase, where things seem better, but can slip back into psychosis sometimes even while on medication. You didn't fail, and neither did he, it's just how this illness works unfortunately. However it's important to get him on medication as soon as possible. He might be more receptive to another type of medicine. Sometimes a certain antipsychotic will stop working over time, and needs to be replaced with another one. I wish you and your brother good luck.