No matter how cruel it sounds, adoption is not going to prevent the ending of two individuals' genetic lineage, as a relevant biological entity.
There is absolutely nothing selfish in wanting to see one's genes preserved. In fact, it is the primary rule of life on this planet.
"We feel we are entitled to have our own child... ...symptom of our own selfishness."
Welcome to the rules of life.
At what price? This may be a normal and natural desire, but it still requires God's cooperation. To do otherwise is manipulative and destructive of life.
You're showing yourself up to be nothing but an anti-Catholic disruptor.