Lionel was given CPR on stage by medics from the Merseyside Water Rescue (MWR) charity and members of the crowd after he fell ill.
He was then taken to Liverpool Heart & Chest Hospital. He spent eight days in hospital.
The drummer, who works as an appliance fitter, said: “I’m so happy to be back on my feet.
“I’m surprised that it happened to me – there were no warning signs or I missed the warning signs.
“I have the occasional flashback and think what if this happened or what if that had happened.
“But I really can’t remember much of what happened. But now I wake up in the morning, and think it is so nice to wake up.”
Former The Police frontman Sting invited the band to play at London’s Hammersmith Apollo on 28 October after Lionel had recovered.
The drummer, who has worked for John Lewis for 15 years, said Sting “gave me a hug” when they met back stage.