by the history you have provided, it seems you probably had developed a rhinolith
( it is composed of calcium salts so may feel like bone) following the attack of cold
which was blocking your nose for some time.
if it got extruded completely, then there is no further treatment needed .
but if a part of it is retained, it may become syptomatic again.
this can be checked by a simple nasal endoscopy
and /or x ray
all the best and god bless.