My son is 24 years old and suffering from social ...

I think you might have to work on his self esteem, He seems like a very sweet guy who is very bright yet scared. If you sheltered him alot while he was younger it might have contributed to the problem. What I would do is set him up in social situations where he would feel comfortable, maybe with a young female who is his cousin! or some of his friends, then slowly build from there.  There are certain people who are very good at dealing with socially awkwardness and others aren't. So prove to him that social situations aren't so bad, however because he is a grown adult this is his problem, and not yours.  

God bless you! 

Melanie

He may need both psychiatric counseling and medication to control this issue.  Have him ask his psychiatrist if there is a medication that he can take to lessen the symptoms while he continues to work on the problem in counseling.