Stressed mom with stressed boy

[Sherilynn]

I have a five year old boy whom I beleive to have seperation anxiety.  He is in kindergarten and in a dual program where he is in school all day.  The first few months he seemed stressed when he came home (understandably) but then it seemed to get much better.  But after Christmas break he came ill with strep throat and then immediately after he came down with bronchitis.  Since then he doesn't want to go to school.  He clings to me.  He cries when and won't let go of me when I try and leave him at school.  I have had to a couple of times just bring him straight home after taking him to school because he is so insistant that he not get left there.  I know the school well enough that I trust the teachers and the school. (No concerns of possible abuse) I have talked with the teachers.  
Any time he wants something he becomes so demanding and insisting that he get it when he wants it as though he can't tolerate any kind of pain whats so ever.  He can't fall asleep without me in the room and his energy is so high that it stresses the daylights out of me.  Help anyone.!!  I love this little boy so much he is a gem but he has some behaviors that seem abnormal to his dad and I.