The greatest burden you could ever place on your family would be for you to take your own life. Their confusion, hurt and guilt would be almost endless (no matter what you told them), for they would constantly wonder what they could have done to prevent such a terrible act, and why you chose to reject their love and concern so decisively.
After all, one of the greatest ways we demonstrate our love for someone is to help them in their times of need—and there is no greater time of need than during their final illness. Don't deprive your family of that opportunity, and don't feel that you are only a burden to them. They love you, and these months could be a time when you and your family grow even closer together. Don't lose sight either of the positive impact your example could make on the young people in your family.
My deepest concern, however, is that you aren't ready to die—either now or later. Elsewhere in your letter, you admit you have ignored God all your life. But listen: God still loves you and wants you to spend all eternity with Him in heaven. And He has made this possible by sending His Son into the world to take away your sins. Turn to Christ today, for "now is the time of God's favor, now is the day of salvation" (2 Corinthians 6:2).