Please help storing baby clothes issue

So I washed, folded and packed my baby clothes in plastic containers and put them under the bed. My girl is now 16mnths old. So everything shed ever worn that didnt fit was packed away. However... To my utter horror when checking on them recently to find a NB dress my sister lent me who is now pregnant, most of the clothes all have yellow stains and discolouration and stink like a musty and plastic smell. I have soaked and washed and resoaked and rewashed.. I managed to finally get the stains out but not that awful plastic storage box smell. Huhh. My gut says get rid if it all and start again. Im not prepared to risk putting these on my next baby with the potential of mold on the clothing or plastic chemical smells. I was going to now vacuum pack clothing but apparently thats bad too because fabric needs to breathe. Please help!!!!! How did you safely store your baby clothes for a future bubba???? I am so guttered this has happened.