6yr old with anxiety?

My 6yr old son gets terribly anxious when we go to any type of gathering outside of school functions..Family reunions, weddings, parties, etc...  He sobs and clings to myself and/or my husband like he's holding on for dear life.  This is around family, people he knows.  
Recently, we went to the movies and it was very crowded.  He was so upset about having to maybe sit beside someone he did not know.  I mean seriously upset.   I suppose I understand him being a bit uneasy about strangers, but this was a breakdown.
He also has this issue with dressing.  He has only a couple of pieces of clothing he will wear w/o making a big deal.  Just yesterday, I had him wear a pair of jeans, and he was a mess.  Once he got off to school, he was just fine, but he was hitting hisself in the head and yelling about how he hates this and that.  
I wish I could explain this better.    Worst of all, I cannot talk to him when he gets like this.  He completely shuts down, won't talk about it whatsoever.  I can't "make it better" and it's making me feel helpless.  

[jdtm]

It is possible that your son is suffering from anxiety - social anxiety to be exact.  Depression and sensitivity issues are often co-morbid with anxiety.  Our child was diagnosed with severe social phobia and depression at six years of age so do not think that six years is young for this issue.  In fact, if anxiety is the issue, I would suspect that your son was born with genetic traits in this area - most anxiety is the result of inherited chemical/transmitter issues in the brain and not from life experiences as many people tend to believe.

I might suggest you google the phrase "anxiety and children" or "social anxiety in children" or similar words/phrases to better understand this issue.  In addition, you might wish to google "sensory integration disorder" or similar words to educate yourself on this problem - you will note that under your posting are several related discussions dealing with clothing sensitivity as this is not an uncommon issue.

You really should talk to your son's pediatrician or family doctor about his fears/anxieties.  If he/she is unable to help, then ask for a referral to a medical specialist with experience in anxiety issues.  If anxiety is the issue, I assure you that your son will not outgrow it nor will it go away; but with proper help, anxiety is highly treatable.  Today our child is doing very well (she is now a teenager) but it did take a long time to reach the point to where she is at today.  In our area, most anxiety specialists prefer to begin treatment with children as young as two or three years of age as the treatment tends to be much shorter and behaviours tend not to be so entrenched.  If you think that I might be or more help, please write.  I wish you the best ...