Otis, my male was like that for a while after he was caught. Part of the problem was, I never had an interest in reptiles before he was given to me, and I was scared of him. I jerked and freaked when he did, and he responded a lot better to my boyfriend, who was used to handling collareds. Otis would allow him to pick him up long before he quit hissing at me. Once after I thought we were buds, he was sunning by the window screen and bit me when I picked him up. (He drew blood and hung on, too!) I started to handle him a lot in the mornings, soon after he woke up and was not real warm yet. Sometimes he was just too fiesty when he was warm. It took about 2 months before we were totally comfortable with each other. Now I can do anything with him, and he likes to ride in a shirt pocket. He also like to sit on my old fashioned huge monitor where it is nice and warm. It is not uncommon to have a tail or three hanging down over my screen these days.
It took about the same amount of time for my female, Saige, to calm down. She didn't bite or hiss, but stayed puffed up and looked terribly stressed all the time. When she finally did cave it was all in one weekend and since she has been a different girl.
Becoming a captive has to be a huge stress. Eventually you will win him over. Good luck! Valerie