Letting go is not always easy.
Letting go of the pain, when he no longer cared. Accept the situation.
Letting go of the offspring, when he wanted to fly on his own. It’s for his own good and yours, too.
Letting go of the past, they will never come back. Accept. Concentrate on the now and the future.
What was right for you then is not necessarily right for you now. Sometimes the hardest part isn’t letting go but rather realising that you have changed, and then learning to start over with your new truth.
Let go and move on.