teen with deadly brain tumour has raised $ 80,000 for emergency surgery .
18-year-old jackson byrnes and his girlfriend jahnae jackson , 18 , are preparing for him to go under the knife on wednesday morning .
he was told by doctors it was too aggressive to operate on .
but jahnae found dr teo who would do the operation with upfront fee .
the couple turned to gofundme to raise the money for the urgent surgery .
the risky operation will likely see him end up paralysed down his left side .