Rob Delaney shares a heartbreaking essay about his son’s death to help other parents of sick children.

Last January, actor-writer-comedian Rob Delaney (“Catastrophe,” “Deadpool 2) lost his son, Henry, after a two-year battle with brain cancer.

Henry was just two-and-a-half years old.

During the painful ordeal, Delaney began writing a book about Henry’s illness to help other parents of sick children. He wanted to remind others that “someone understood and cared” about their pain.

However, Delaney stopped writing the book when he learned Henry only had a few months to live. He wanted to spend as much time as he could with his son and family.

“I stopped writing when we saw the new, bad MRI,” Delaney wrote. “My wife and his brothers and I just wanted to be with him around the clock and make sure his final months were happy. And they were.”

Eight months after Henry’s death, on September 18, Delaney sent out a tweet with a link to excerpts of his unfinished book he posted at Medium. “I hope this helps,” he tweeted.

The passages shared by Delaney reveal the toll a terminal illness has on a family.

I’m so fucking tired. The front of my head feels like it’s stuffed with hot trash. My chest and throat feel constricted and I’m reminded that while my life is and will remain stressful for the foreseeable future, I could at least lose some weight to reduce my heart’s workload, so a cardiac event doesn’t take me out before I turn fifty.

In the essay, Delaney discusses how the treatments affected his young son’s body.

The surgery to remove his tumor left him with Bell’s palsy on the left side of his face, so it’s slack and droops. His left eye is turned inward too, due to nerve damage. But the right side of his face is incredibly expressive, and that side brightens right up when I walk into the room.

Delaney also highlights the important role that caretakers played in keeping his family sane throughout the ordeal.

I’ve gotten to know his tracheotomy nurse rather well. She was a colonel in the British Territorial Army and served in Iraq and Afghanistan. She also helped turn Great Ormond Street Hospital for Children into a triage unit for adults on the day of the bombings in London on July 7th, 2005, which killed 52 people. So even though I fucking hate what she’s taught me to do to my beautiful baby boy’s neck, I’m grateful to have her around to talk me back to sanity afterward.

Then the essay abruptly ends.

The above was part of a book proposal I put together before Henry’s tumor came back and we learned that he would die. I stopped writing when we saw the new, bad MRI. My wife and his brothers and I just wanted to be with him around the clock and make sure his final months were happy. And they were.

Last June, Delaney and his wife, Leah, learned they were having another baby.

His positive experience with England’s National Health Service encouraged him to ask all Americans to fight for Medicare for all.