I have experienced exactly what you are talking about with my Cyclura hybrid. I acquired him from a family that got him as a baby and became scared of his threat displays. He ended up in a cage covered by a sheet for over a year until I got him. Now 2 years later he is very personable. Continue with making your presence known, but don't push the envelope. DO NOT subdue him or force him to do anything that he seems sketchy about. What worked for me was allowing mine to eat right next to me and slowly placing my hands closer and closer to him. Whenever I was in my reptile room I would open his cage and go about my business like he wasn't even there. After a couple months he was approaching me, smelling and investigating. Now he follows me around. After you develop an understanding he will get much better. Just invest the time for him to realize you are not a threat. It will get better. All Cyclura have different personalities and some will always be more trusting than others. Good luck.