That's a difficult thing for anyone to deal with, especially with lockdown, two more tumours and his recent stay for major surgery at Starship hospital.
"There's only so much I can take," Jacob says.
The teenager is doing his best to cram a lifetime's worth of experiences in the time he has, and his family are doing their part to raise money by having their heads shaved this weekend.
"Normally, it's Jacob who has no hair but now it's going to be the rest of the family that has no hair," says his mother, Amanda.
When he was first diagnosed, her sister had her head shaved, but Amanda was reluctant.
"I said if it comes back, I'll do it," she says, and Jacob has held her to that promise.
"We kind of think it's like he's been through huge amounts worse than us losing our hair for a little bit."
A few others have also stepped up to contribute and the event will be held at Totara College on Saturday at 10.30am.
Jacob has already volunteered to man the barbecue.
Jacob Coker missed seeing the famed Southern Lights due to lockdown. Photo NZME
The family are hoping to raise enough to fulfil a few of his dreams, such as going up in a fighter jet, which was supposed to be happening in early November.
However, with the current Covid levels, that adventure looks to be in doubt.
He has already had to face the disappointment of not being able to go to the Southern Lights, thanks to Covid, but there are far worse things to deal with, he says.
For now, he knows he has a few decisions to make.
"I've got a lot of big decisions to make involving surgeries and stuff. Not fun conversations," he says.
Conversations Amanda feels are something she should never have to have with her child.
She says he's undecided whether to have more surgery to remove the two tumours.
"There will just come to a point where he'll say enough. Stop taking them out."
The one stipulation Jacob has is that he wants to do as much as possible at home, rather than spend all his time in hospital.
"I love the staff up in Palmy. They're amazing. But you can only like sit in a room for so long before you go crazy."
Covid restrictions had also made it a lot harder because he was unable to have visitors.
Despite all of this, he still manages to find some humour in the situation, even if it is a little dark.
Amanda says when he was about to undergo surgery, he managed to make a joke.
"They were putting the gas mask on him and they kept taking it off and putting it back on and he says 'oy, can you stop that, because you're wasting the good stuff'."
She says it's their way of coping.
The family consider themselves lucky to have good friends and to be living in a great community like Dannevirke.
When she and husband Greg went to Auckland with Jacob for his surgery, Greg's father stayed with the other three children and there was always food dropped off at the gate.
"The Dannevirke community's amazing. They've helped so much."
For details on the Shave for Jacob event, see facebook.com/events/295880015364940/.