I think I have depression but I don't know. How do you diagnose yourself?

Signs of Depression. It is probably better to seek a psychologist or a psychiatrist to do an evaluation and provide treatment if you need it. Signs of depression are: persistent sadness, lack of interest in daily activities, change in sleep pattern, weight changes, lack of energy, feelings of worthlessness and other negative feelings, thoughts of suicide or death.
See a psychiatrist. U don't have 2 try 2 diagnose yourself-- go 2 an expert who can help u.