How has your knowledge of the Plan of Happiness changed/benefited your life?

My wife and I married when we were 18 when we already had one daughter. We became somewhat complacent in our dedication to the gospel and our personal lives took a turn away from church. My wife also became pregnant with our second child at the age of 18 and we were excited for the new addition to our family. We were living with my parents at the time and looking to our first home.
Sienna Lynn was born on July 1st, the same day as my wife's birthday. She was a strong girl and very alert and awake. Shortly after she was born, we moved into a small 2 bedroom house and got settled in. I remember tasking turns with my wife to get up in the night to feed and care for Sienna, who never seemed excited to sleep. September 18th I fed her at 4:18 in the morning and put her back to sleep. That was the last time I saw her alive. I remember going to wake her for family pictures we has scheduled that day. Instead we spent most of the morning at the hospital as doctors tried to revive her.
Going through that experience was difficult for us as a couple and a young family. However, despite the heartache of her not being with us anymore in this life, we were able to draw nearer to each other and the Savior. The plan of Happiness teaches us that through our faithfulness we can return as an eternal family to our Father in Heaven to live together with Him. It was one thing to be taught a certain principal your entire life, but to be tested against it is different; the love and strength I have found for my wife and my family is greater than I could have anticipated.
My wife and I changed our lives immediately and took the opportunity to become an eternal family by getting sealed in the temple with our daughters.
Today we are the happy parents of 5 daughters who love the Lord and the teachings of His gospel. I know that we will see and live with Sienna again if we endure to the end and keep the commandments. I look forward to that day.