Jesus died. Completely. He fully suffered death, the penalty of our sin, on our behalf. He took on our fiercest enemy and defeated it so that death, for those of us who place our faith in him, will simply be an instantaneous transition from this life to the next.
When you feel doubt, move away from your feelings, which can change hour upon hour, and move your faith into the facts of Christianity.
Because of the death of Jesus on the cross and his resurrection, you get to walk in victory over life and death, sin, and the grave forever. So be positive.