Hi,
I have no experience with mental health problems. However, I have recently begun studying the pH balancing programme as recommended by Dr Robert Young in his book The pH Miracle. I am very excited about this book and thought I would recommend it to you as he does document examples of people suffering from mental illness, including schizophrenia who have been greatly helped by this diet programme. He explains that there is only one disease which has many different symptoms. My symptom is eczema. The one disease is the over-acidification of our bodily systems. You mentioned that your diet is high in sugar, this no doubt has lead to internal candida which thrives in an acidic body.

May you find the strength and patience to heal yourself.