You must have had drying of nasal cavity
or infection..causing the stuffiness.you have not mentioned whether it was a dry palce or humid one you visited.the blowing traumatised your nasal skin or the infection may also have caused the bleed.The lumps and scabbing are residual clots in the nasal cavity.please donot pick your nose,may cause further bleed.There are two options.you may treat yourself and see or you may take an ENT CONsultation immediately.If u want to try medicines first,take a course of antibiotic,like cefixime
200 twice daily for 1 week,with cetrizine
half at night and a saline nasal spray
,like solspre' 3-4 puffs in each nasal cavity 3-4 times daily,which will loosen the clots and scab and open up ur nose.please donot blow.If U are relieved with this there may not be a neeed to see doctor immediately,unless you are hypertensive,or have further bleed.