The 37-year-old became the latest football star to test positive for the virus after he started developing its associated symptoms.
All sporting activities in UK have been halted following the outbreak of the disease which originated from China in December.
Reina, who is on loan from AC Milan, has shown signs of recovery in recent days but has revealed some horrific details of how he felt earlier.
'I am winning the battle against coronavirus only now,' he told the Italian publication Corriere dello Sport.
'The most difficult moment was when I could no longer breath, the 25 minutes I ran out of oxygen. It was the worst moments of my life.
'I don't miss the company as it's me, my wife Yolanda, five children and two in-laws. The house is big and loneliness has no access to my home.
'I was very tired after experiencing the first symptoms of the virus. A fever, dry cough and a headache that never left me - it was just that constant feeling of tiredness.
'The only real fear I had was when I understood that there was no oxygen: endless minutes of fear, as if suddenly my throat had closed.
'As a result I spent the first six or eight days indoors.'