I found mold in the humidifier next to my bed. no idea how long it's been there. haven't used in a year. i've been getting coughs. will i be ok?

Unlikely a problem: There are thousands of mold strains and only a few rare ones that are toxic.You wil find mold almost anywhere that has moisture to sustain it, including humidifiers that are not cleaned regularly. I would clean it and forget the issue.It is not worthing sleep over.The next time you take a deep breath outdoors you have inhaled some mold spores.It's no big deal.