The Spaniard announced last week that he was recovering from COVID-19, also expressing his anger at how British authorities responded to the outbreak.
Speaking to Corriere dello Sport, Reina said: "I am winning the battle against coronavirus only now.
"The most difficult moment was when I could no longer breathe, the 25 minutes I ran out of oxygen.
"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.
"It was the worst moments of my life. I was very tired after experiencing the first symptoms of the virus."
On returning to football, he added: "Football takes a back seat. I don't care much, really. Everyone's well-being goes above anything else.
"I will be a supporter of playing when everything is in the best conditions, that everyone is safe. Football cannot be a priority right now. It is not important to finish this league.
"I know and am aware of all the interests that exist around soccer, especially economic ones. But there are also many other areas, and right now the first thing is people's health.
"April 30 as an option for the Premier League to return seems to me that it will not be a real date and I think we are going to go much further."