Well said.
The only meaning is what we create ourselves. It will only exist in our species' timeframe, thus we will never be immortal. Unless...
The only way we can ultimately have any meaning is by spreading intelligent (and even microbial) life throughout the universe. As Carl Sagan said, we are star stuff. We are made of the same elements as the stars. We are the universes way of knowing itself. We are the moral children of an amoral universe.
One of my major peeves is when people use the term "contamination" regarding spreading life to other planets. Bring life to dead planets is probably the only meaningful thing humans can do in our small timeframe in the universes' history.