“Passages in Caregiving” by Gail Sheehy, c. 2010, William Morrow, $27.99, 397 pages, includes index.

These were supposed to be the best years of your life.

With the kids on their own and the mortgage paid, you were looking forward to spending time with your spouse, traveling, finding a new hobby, getting to know one another again.

Then the diagnosis arrived.

Suddenly carefree plans are replaced with caring for spouse or parent. That, says author Gail Sheehy, is when you need to reach out because you can’t do it alone. In her new book “Passages in Caregiving,” you’ll learn more.

Clay Felker was already a legend when Sheehy met him in 1965. He was a powerful editor and magazine creator, a “life-force.” She was a young reporter who was attracted to him instantly.

After a whirlwind courtship of 17 years, they were married. Not a decade later, Felker was diagnosed with cancer for the first time and was successfully treated. When the cancer returned repeatedly, Sheehy, herself a journalist and author, learned that life would never go back to “normal.”

In about one-third of American households, someone is acting as caregiver. The average caregiver is a 40-something woman who also holds down a full-time job. In all likelihood, she still has dependent children at home. Her role lasts an average of five years and during that time, she has a good chance of having health problems of her own due to stress.

Sheehy likens the path that a caregiver walks to a labyrinth and she says that, much like Elisabeth Kubler-Ross’s stages of grief, there are eight “turnings” that a caregiver walks. You will be shocked and fly into action. Once the crisis has seemingly passed, you’ll settle into a “new normal” until the affliction or need for care “boomerangs.” Back in caregiving mode, you’ll think you can do it all alone, but you’ll realize that you can’t. You’ll be frustrated. You’ll learn to say goodbye.

In between, Sheehy says, take abundant notes. Ask for help. Watch for depression in yourself and your loved one. Take advantage of local programs and agencies. Don’t even try to be a silent hero.

Looking ahead for what-if? You should be. And you should read this book.

“Passages in Caregiving” is a love letter and a eulogy wrapped up in bedlam and education, disguised as a useful self-help how-to. It’s instructional, down to the details, which pushes it beyond merely helpful. It’s going to make you spitting mad, and it’s going to make you grieve. And it’ll make you think even further into the future: who’ll take care of you?

The Bookworm is Terri Schlichenmeyer. Terri has been reading since she was 3 years old and never goes anywhere without a book. She lives in West Salem, Wis., with her two dogs and 9,500 books.