You dont need your parents permission to get help. You can talk to counselors at school and there are crisis lines you can call. They might even be able to tell you about some depression support groups in your area that you could attend.

About your blood sugar, have you been checked for any kind of infection? Have you been running a fever, even low grade? Is your nose runny or stuffy. Aches and pains? Skin irritations? An infection can cause your bloodsugar to fluctuate like mad.

There are links between diabetes and depression. The out of control blood sugar has metabolic effects on the brain causing depression, and the depression leads to stress that causes blood sugar to rise, causing more depression. It is a vicious circle. If your mother won't help you, you can always call the police and tell them you want to kill yourself. They will automatically take you in for an eval and a 72 hour hold. Not the greatest wat to get treatment, but it beats no treatment.