Several rounds of chemotherapy have left him depleted both physically and emotionally, and he’s lost both his hair and his sense of taste.

But the one person staying steadfast by his side — the one who cried tears of joy with him when he recently learned his tumors were already shrinking — is his wife Jean Currivan, 54, to whom he’s been married for 29 years.

“Jeannie is wonderful,” he says in PEOPLE’s new cover story. “She cried of course this morning when she got the [good] news [about my tumors shrinking]. But it’s been a lot. It’s a lot of pressure.”

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“My heart goes out to caregivers,” he says. “Because they have to deal with their loved ones suffering and they also don’t always know how to help because there’s not much they can do, except try to make you feel more comfortable, at ease and not worry about ordinary stuff.”

For more on Trebek’s treatment progress, pick up a copy of PEOPLE, on newsstands Friday

The 78-year-old Jeopardy! host, who has admitted to struggling with depression since the diagnosis, adds, “They’ve also got to be strong and not allow their mate not to feel like they’re downhearted too.”

Trebek and Currivan have two children together — Matthew, 28, a restaurateur in New York, and Emily, 25, who works in real estate in L.A., — and consider themselves homebodies who prefer staying at home watching movies rather than going out to parties.

As for how the children are faring while their dad works on making a recovery?

“They look at me as Mr. Strong,” Trebek says. “They think, if anybody’s going to beat this, dad will. They’re very positive, and until I demonstrate otherwise, they’re going to continue in that vein.”