The young entrepreneur, who became the seventh person voted out of the house on Friday, confessed that seeing his message destroyed in the 'love letter bomb' task was almost enough to send him packing.
"I said to a few of my friends in the house that when I didn't get that letter, I was literally about to walk through the Diary Room door and say I'm leaving," he told Emma Willis on Big Brother's Bit on the Side.
"I'd got the words in my mouth, I was going to say, 'There is nothing I want more than to see my girlfriend, I don't care about the process, I just want to go home'.
"And then I got in the Diary Room and sat down and I was like, 'You know Harry, it's a few weeks, she sent you a letter so obviously everything's fine. It's only a letter, it will be alright'."
Although he almost let his emotions get the better of him, Harry stated that he mostly saw life in the house as nothing more than a game.
"At the end of the day it's a gameshow so you have to go in with a gameplan," he said. "Week one evictions came up and everyone was crying when someone got evicted, I was like, 'You've known them five days, who gives a damn?'
"I was like, 'Just remember guys, it's a game'. We've got to evict people at the end of the day, that's what we're here to do."
> Big Brother's Harry Blake: 'I don't regret pranks and fights'