I'm trying to picture how you crochet with only one hand, it must be very difficult to do.
Well I use the other hand to hold the project The reason why I don't crochet properly is because I learned myself from a pattern that had a "how to crochet" section. It had pictures of the position of hook and yarn, but not the position of the hands! Since I'm primarily a knitter, I just did as I do when I knit! It's only a while later that I observed a friend crocheting and I was like "OMG, how do you go so fast?!" But I couldn't unlearn the way I was doing it!