Did mine once,about 6 years ago,was in agony,did a few more things to my body at the same time.
It took months to get better,I thought i had broken my ribs,but the x-rays said i hadnt,this is when they told me i had the same as you,It is very painfull,but does get better in time.
I did mine on a 6ft wooden drop,was a slow drop and i went to wheelie drop and the rear wheel span on the wood,i nose dived off and basically folded myself in half on landing,i felt something in my rib cage letting go.It was painfull enough to put tears in my eyes.and hurts to cough and breath,just make sure you dont sneeze,Its not good and very painfull.