8 year old with severe anxiety

We have been having issues with my eight year old stepson for several years.  He is a wonderful child and he is very bright and intelligent.  He is at our home two nights a week with his three year old sister.  I have two boys  ages five and nine.  He seems to have a high level of anxiety for his age.  For instance he seems to be afraid of just about everything and he is very clingy.  He follows me or my husband around constantly and if my boys are at their fathers house he doesn't seem to know how to play by himself. He cries very easily and becomes very emotional about very minor things. We have recently noticed that he is constantly pulling on his penis.  

     He has also been urinating in strange places.  It started when he was around five years old.  The first time we were called by his kindergarten teacher and she told us he had urinated in the school sink.  She also told us it happened several times prior but at the time she was not sure which student was the culprit.  He was reprimanded for his behavior and we explained it was also unsanitary.  The behavior stopped for over a year but then we found urine in the bathroom trashcan and urine in the tub toys in the shower several times.

      I am not sure how to handle the situation.  Any advice would be helpful.  
  

[Gina04]

Has he been evaluated by a developmental specialist at all?  Aside from the urinating issues, he sounds very much like my four year old who has Asperger's Syndrome.  One of the symptoms of Asperger's is that they don't really have common sense.  Is he urinating in these places because he is angry, wanting to upset people, etc. or do you know?  It could be that he needs to go to the bathroom and that for some reason it makes more sense to him to just go in these places.  Do a search for Asperger's Syndrome symptoms and see if they describe him at all.  Whether they do or not, I would recommend having him seen by a developmental specialist.  It was just helpful for me to have an idea of what might be going on with my son and then ask the specialist specifically about the possibility of those things.

[jdtm]

Our child suffers from severe anxiety and has been treated by professionals for several years.  Some of your posting reminds me of behaviours which describe anxiety; however, the overall "picture" of your stepson appears not to be that of severe anxiety.  I also wonder if your stepson might be on the autistic spectrum - whether Asperger's or PDD-NOS or a lesser version, don't know.  I do believe Gina04 is correct in that having your stepson evaluated by a developmental specialist might be a prudent decision.  I really believe there is far more going on here than "anxiety" behaviours.  Perhaps autism, perhaps not .....