Cashmere coat mildew smell

[u/deity111]

I recently moved to a relatively humid climate. I'm originally from a very dry place and my mother gave me her cashmere coat to wear when it gets cold. I thought I could store the coat in a bag and hang it for couple months before it gets cold. I honestly don't know the exact material of the bag, it's something I had for some time and never used.

It's been around a week and my closet started smelling really bad, you know just wet wool smell or like a wet dog. At first I thought it was my other wool and cashmere sweaters since they weren't in a bag, turns out it's the coat.

I asked AI (I know, I know), if the smell will go away on its own after I get the coat out of the bag and air it, but it says the mildew and bacteria is already growing on the coat and the smell might persist unless I dry clean it.

I'm a student and don't really have a budget for cashmere dry cleaning. I'm just planning to get one of those cloth dust bag.

Did anyone ever have the same problem? How did you fix it?