Thanks for the info, Also I wanted to let you know that he is in kindergarden so he goes to school from 11am till just after 3pm, M-Thur
Have you thought of arranging regular playdates with some of his friends from school? perhaps if he could have a friend over one week and go a friends house the other week, he may gradually detach from you. keeping a regular pattern may be just what he needs and soon enough he'll be so into playing that he'll forget your there.
Also, just encourage free play in general, for example, give him your time in the afternoon, then calmly explain that it's 'quiet time' and he is to amuse himself. I guess what i'm trying to say is, gradually encourage him to be more independent. hope it all goes well :)