Your life is your choice. If you tell your family, they might try and move you to an institution. Certain people don't believe you have the right to die no matter how much you suffer. It sounds like you don't really want this to be your decision. You should find a support group. I have suffered with depression, all of my life. I have many health issues and hope I have the guts to go on my own terms when I can no longer take care of myself. I will, I hope, be able to explain it in a letter that they will find after the fact. Wasting away is no way to go.