George Shelley "pretended" his sister's death "didn't happen".
The former Union J singer was left devastated when his sister Harriet, 21, passed away after being hit by a car last April and though he tried to carry on as normal, the tragedy hit him hard and he embarked on a downward spiral that saw him isolate himself away from his friends.
He said: "I've had a pretty rubbish year and I've experienced things I thought I'd never have to experience...
"I just pretended it didn't happen. I was doing things I shouldn't have been doing because I wasn't well enough to."
But George is getting his life back on track now.
He added in an emotional interview on 'Lorraine': "I'm seeing colour again.
"I wasn't eating. For so long, for months, I was in my bedroom, the lights were off, there were takeaway bags everywhere.
"And then one morning I woke up and the sun was rising and it was shining on a picture of me and my dad and I thought, 'OK, let's go and do something now.' "
Harriet was intoxicated when she walked out from between an HGV and a coach carrying crew and equipment for a Stormzy concert and was struck by a car, causing her to hit her head on the ground.
The midwifery student was in intensive care immediately after the accident, which initially gave the 24-year-old pop star hope she would pull through.
He recalled: "She was having a standard night out, just drinking, you have to be so careful with alcohol guys.
"So innocent. She just needed a wee. She ran out between two tour buses, I believe they were Stormzy's tour buses, and she ran out and it was a silly mistake.
"It was nothing to do with the car. She fell back and hit her head on one of the buses. She was in ICU for a week, watching the brain pressure go up and down. It was like 'she's gonna live'.
"Then at the end we had a brain specialist in and they said even if she pulls through she's gone. It was just like wow."