The Ivory Coast international, 33, collided with Canaries goalkeeper John Ruddy in the Barclays Premier League clash at Stamford Bridge last month and was told by the club's medical staff that he was unconscious for "six to eight minutes" afterwards.
Drogba, who could return to action for the Blues at home to Swansea on Saturday, told The Sun: "I was scared. I couldn't remember anything from after Norwich equalised until I was being rushed to hospital. I didn't know what was going on."
He added: "But I'm really grateful to everyone who helped me, the stadium staff and the medics who calmed me down. They told me I'd been unconscious for between six to eight minutes.
"I've had some injuries before - I've broken a leg and arm but this was worse. I had concussion and a perforated ear drum which is why I needed time. I was feeling dizzy and needed to wait for my ear to heal.
"I couldn't cope with any noise, it was too noisy in my head and I wasn't allowed to fly because it was too dangerous.
"Not playing was frustrating, but I was lucky I was still alive and I knew it was only a question of time and I'd play football again."
Source: PA
Source: PA