Chest painning

Since morning when I woke up
My chest started to pain
Until now

Every action I did
I will feel the pain in my chest
When I breath deeply
When I stand up
When I sit down
When I laugh
When I bend my body

The action that won't cause the pain is
Sitting still and not doing anything physically
Doing things mentally are allowed
This is the reason why I act strange when I reached the school
But no one ever notice that I'm strange?
Whatever
It's my businness