Boyfriend help!!

I was giving my boyfriend a hand job for 45 minutes and I did all of his favorite things and I know he liked it cause of the way he reacted and he was about to cum like 5 times but it never happened. Does anyone know why this is happening? I talked to him about it and he told me it has nothing to do with attraction or lack of interest and not to worry about that but I’m worried can someone help me?