Not all guys shy away from having a second family. I got remarried again again in my forties, and had 2 children, one when I was fifty. But I love raising kids, even age my age. They are a blessing. Though I can understand why everyone may not want to raise children at this point in life.
It helps that I am very fit. I can't imagine doing this if I had the declining energy of many folks my age. It can be exhausting enough even though I'm in fairly good shape.
As with everything else in a Christians life, the key is to rely on God and pray through challenges and to also utilize the joy of the Holy spirit that God has gifted us all with.