Now Nik says his attitude to life - and death - has changed and he is grateful to have seen his children grow up. His eldest daughter is engaged to be married.
Under the proposed law, Nik is concerned that other people suffering terminal illnesses would choose an assisted death and miss out on the joys that more life could bring - even if they are less physically able.
The private members' bill was put forward by Labour MP Kim Leadbeater but the deeply sensitive nature of this issue has split politicians in all major parties.
Prime Minister Sir Keir Starmer has promised his party will be allowed to vote freely with their conscience.
Many people living with terminal illnesses have said the bill offers them hope that they may not have to experience a painful or prolonged death.
Elise Burns lives in constant pain due to terminal breast cancer that has spread to her bones, lungs and liver. She has been told she might have only two years to live.