Harrison has already met his goal, raising $8,330 (£6,314).
‘It’s beyond luck, karma, blessed, whatever you believe in,’ he said. ‘I honestly never thought I would get to this point in my life.’
MORE: Morning Face: Disability and lifestyle blogger Sarah Alexander shares her morning routine
MORE: What I Rent: Tom, £1,733 a month for a one-bedroom flat in the Barbican Estate
MORE: Man’s story about a missing cat will bring some joy to your day