The 45-year-old Dunedin truck driver made the decision for surgeons to remove his right leg after a crash on State Highway 93 near Mataura on June 1.
"It is unbelievable how many pieces of paper you have to sign to get your leg off."
He has endured major surgery five times, ranging in length from six to 18 hours, 23 blood transfusions, skin grafts, countless hours of rehabilitation and the ongoing effects of a head injury.
But it is the absent leg that is proving the most frustrating.
"I have sore toes and the top of my leg feels like a million pins pricking you, and that is what I feel every day - and that is the worst pain of the lot.
To alleviate the pain, he was undergoing mirror therapy in a bid to reduce the phantom limb pain experienced after having a lower limb amputated. The therapy involved the use of a mirror to trick his brain into believing his leg was still there.
"I didn't believe them ... but it does work."
While full of praise for the care he received from surgeons and nurses at Dunedin Hospital, he decided to return home late last month.
"I am not meant to be here [at home]. I am still meant to be in hospital for another five to six months, but I have only lost three-quarters of a leg."
For now, he was wearing compression bandages and would be issued with a trial leg, while a prosthetic limb allowing him to drive automatic vehicles was possible within two years.
A goal is to return to driving trucks: "I have to get on the pony, but whether I can drive professionally again ... I don't know."
Despite the ongoing support of ACC and his Auckland-based trucking employer, he and partner Tina were facing the unexpected financial hit of having to buy a home to accommodate his mobility needs.
It was frustrating not being able to do all the things he took for granted, but he was determined to look at things positively - after all, he was lucky to be alive.
Mr Campbell was driving his Kenworth laden with fresh fruit and vegetables, when he hit a Highland cow standing on the Clinton-Mataura back road about 3am on June 1.
"I remember hitting the cow because it was a big loud thud, but then somehow I got knocked out.
"I have had horses running beside me ... and I have seen a couple of cows on a road, but it never dawns on you that you are going to hit one one day."
He does not know how long he lay trapped in the truck cab - possible 10 minutes or more - but was "bleeding out" before three fellow truckies came to his rescue.
A local policeman, whom he was yet to meet, later applied a tourniquet to his leg, a move that is credited with saving his life, while emergency personnel cut him from the cab.
He was then flown to hospital by the Otago Regional Rescue Helicopter.
"I have a lot of people to thank."
