What actually happened at Karbala

What you are stating is immediate reaction of any human on hearing terrible news. This action ‘lasts’ for a few hours or so until the person comes out the initial shock. The action of Hz. Bilal (ra) and that of Hz. Aisha (ra) was the same after knowing of Prophet’s demise.

They did not make an annul ‘Chest beating and face slapping’ ritual/event!

Do you have any record of it being repeated every year from then on as a must ritual as practice by the 12ers?

Don’t tell me that you are following sunnah of Hz. Aisha (ra)!

Why not hold Mataam in honour of Prophet’s death as brother cricketplaya suggests?