He also lost 10kg and still struggles with his fitness levels.
But it could have been much worse.
"If I had landed just two steps to the right there was steel ... It's not really something I try to think about."
Sometimes it is unavoidable, though, such as when a scar on his back is visible while sunbathing.
"People ask how I did it and when I tell them, you can just see their faces ..." Mr Stilwell says.
He says he was "an absolute tool" for trying to get into the apartment the way he did.
But the experience has taught him valuable lessons. "I definitely appreciate life more and treat it with more respect."
He was now going to avoid doing such "foolish" things, and was split between thinking about how lucky he was and if it was just fate he survived the way he did, he said.
After his accident he met his neighbour Geraldine Bautista, from whose balcony he fell.
He had lost his keys after a night drinking with friends and wanted to get into his apartment when he came up with the idea of dropping from one balcony directly on to his own.
"We talked for about an hour. I had some questions [about what happened] ... She felt so guilty but I assured her it was not her fault at all."
He has no memory of the fall or events leading to it.
His first recollection is when he regained consciousness in the intensive care ward at Auckland City Hospital. "I asked the nurse what happened and she said I fell from my balcony ... And I remember thinking "but I live on the 14th floor".
And the first he knew about the circumstances of the fall was when he read an interview with Ms Bautista in the Herald. "I couldn't believe it."
His mother flew from England to be with him and he was still quite fragile when she left. He knows now he's liable to "get a slap" if he ever tries anything similar again.
Despite his ordeal, Mr Stilwell has fond memories of New Zealand, the friends he made and even the medical system.
"I had such great care from everyone and I want to thank all those who looked after me and ACC who were so good to me because after the accident I could not work, so had no income."