My son has social anxiety. How can I help him?

I'm not sure if this started at the same time as Leiby A"H but it definitely started in the summer. My 9yr. old ds would get stomach aches before he left the house. This went on for months, he didnt want to got to school, when we went out, he needed a bathroom wherever he went. He would call me from school to pick him up early. B"h in the last few months he has been good about school and staying but he refuses to play at other peoples houses. As soon as he goes I have to come and get him bc his stomach starts to hurt. Shabbos he only wants play dates here he never leaves the house. He doesnt want me to tell the neighbors what is wrong , but he refuses to go there all the time..I hate making up excuses. When I leave the house at night which is not too often but lets say I have to go to the Mikvah...he wont go to sleep until I come home. When I had PTA the other night he stayed up until 10 with his face pressed up against the window. Once we had a babysitter, he couldnt eat supper bc he was so nervous. Now his friends dont invite him anymore and Im afraid this will stunt him socially. I've asked him why he thinks this happens but he doesnt know. (and yes I've asked him if anyone has ever bothered him....).

If he won't talk to you, maybe he'll talk to a professional. A child psychologist might get more out of him and help him work through his issues.

Please talk to a professional about this.