At Azaylia’s funeral last Friday, Mr Cain told mourners his daughter was “beautiful, strong, courageous and so, so inspirational”.
Sharing footage of the memorial on Instagram on Thursday the 30-year-old said it was the “toughest speech of his life”.
He said he wrote it at 4am couldn’t bear to read it back “because of the pain it caused”.
In the speech Mr Cain said: “I always thought I was a bit of a celebrity, then Azaylia came along, completely blew me out of the water.
“I think that when you have a child, as a parent, you can be slightly biased, but I think it is safe to say, on behalf of myself, my partner, to my friends and family and the whole world who have followed our story, that my daughter, Azaylia Diamond Cain was special.
“Beautiful, strong, courageous and so, so inspirational. I don't think that a single person in this room can say they are too wise, too educated or experienced to have learned something from my likkle lion.
“From the second she came into my life everything changed. She changed my life, she saved my life and she made my life.”
Reflecting on the moment she was diagnosed with cancer Mr Cain said: “I don't understand after hearing that news, after getting the most devastating news, at such a difficult time, we still had the best days of our life.”
He said he missed kissing her lips, smelling her head, I miss blowing raspberries on her belly, and putting her feet on his face.
Azaylia was diagnosed with aggressive leukaemia when she was eight weeks old and a fundraiser to try to help save her life had reached more than £1.5 million by the time she died.