Because it's a heart disease. But you still know that you are sad, so you come to the internet for help. In fact, the best way is,
You have to accept that you are sick first, and then admit that you will be fine if you take medicine. Don't pay attention to your illness all day. Focusing on one thing for a long time will make your whole body and mind nervous. All you have to do is relax, do what you want to do and keep yourself busy, even if it is simple household cleaning, laundry, cooking, shopping and so on.
Schizophrenia, if it is not a genetic disease, is generally a stress disease caused by a lot of worries suppressed in the heart for a long time. The best way is to keep yourself busy, so that you have no time to think about your illness, and then practice more quietly, exercise more, eat less greasy food, rest more, and get better easily and quickly. I wish you a speedy recovery. Don't be afraid to be better.