Based on your set of symptoms, it does not seem as though you are experiencing psychosis. Psychosis is a break from reality. Individuals with psychosis, for instance, may believe that a device has been implanted in their leg or that the government is secretly recording their every move. Your symptoms seem more characteristic of bipolar disorder. Individuals with bipolar disorder describe having cycles of highs and lows, with regard to their mood. Follow this link to learn more about bipolar disorder.
Your body image issues are also concerning. Your body cannot sustain a healthy level of functioning when only consuming 500 calories per day. You are rapidly losing weight and have a distorted view of your body. Those aforementioned symptoms are signs of an eating disorder, namely anorexia. Eating disorders are the most dangerous of all mental health disorders.
I do not have enough information about your symptoms to determine if you have any of the disorders that I have discussed. The only way to determine whether or not you have a psychiatric disorder is to be evaluated by a mental health professional.
You are suffering both psychologically and physically. Your health is being compromised by a lack of adequate food and proper nutrition. It is imperative that you seek treatment immediately. The longer that you delay treatment, the more your mind and body will suffer. Please consider my suggestions. The find help tab, at the top of the page, can assist you in locating a mental health professional in your community. Please take care.