Re: Oh dear lord i need help!
Could you try confining him by a baby gate or something (just so he's not climbing onto you) then playing nearby with the other kids and shouting occasionally "This is so much fun! So-and-So can join us when he stops screaming and we can all have fun." Get back into the games/activities then repeat a zillion times every minute or two.
A (usually) happy wife mama to my BOGO girls, DD1 July 2010 and DD2 Dec 2011.