Ariana Grande fan Mr Shillito, 21, of Wakefield had travelled to Manchester Arena with his girlfriend Chloe Coopland, also 21, to see the American singer in concert.
Former Ossett High School student Mr Shillito, who works as a bus mechanic for Arriva in Wakefield, was about 20 metres from the explosion.
Mr Shillito said: “There was a huge bang and everyone just stood in shock for a few seconds. It was like a living nightmare.”
He escaped physical injury but experienced low moods and could not sleep after the attack.
Mr Shillito had weekly counselling sessions for four months after being referred by his GP.
He said: “The counselling helped me a lot. I didn’t think I would get out of the way I was feeling, but the counselling helped bring me back to how I used to be.
“I have been dreading the anniversary coming around. I’m worrying it is going to happen again, it still affects me day to day.”
Mr Shillito said he plans to spend the day of the anniversary with his family. He added: “It took me at least five months to get back to something like normal. It was a constant low.
He wanted to raise money for those affected by the bombing and completed a 50-mile sponsored cycle ride from West Yorkshire to the Manchester Arena in March this year with his friend
Tom Miller. They raised more than £1,000, with half of the cash going to an emergency fund to help those injured in the attack and the rest going towards a permanent memorial fund.