It's hard for me to grasp this concept, you're suffering and don't want your family to suffer, but it will happen.
If you don't commit suicide, and live happily until old age, you will witness the death of everyone in your family and endure probably the worst. Maybe one dies with cancer, horribly, you just don't know. Maybe you're dying or get into an accident and they start to hate you because you're basically 100% handicapped and don't want to care about you then. Humans are a disgusting species, it just doesn't matter at all in the end.
Misery and despair are part of life and death, but death is the last station, the last act of enduring all that.
Do whatever you want be 100% sure but life is just a stretched way of the universe to say fk you.