After weeks and weeks of trying to brush off the niggling concerns, I am blessedly and finally and utterly at peace.
The Rov told me that according to the Torah, if both a 70 year old and a 20 year old are in danger, there is absolutely no preference as to whose life takes precedence.
That's it; it's all over now.
And now I can go into this with strength, confidence and pride, the powerful beams of Torah light guiding me and protecting me.
Baruch baruch Hashem!!