How long can I store my breastmilk?

For some context, no one will be consuming this breastmilk, but me and potmy partner. I'm a surrogate and just gave birth on Thanksgiving. The baby is already on the way to his family and the family has chosen to formula feed. The thing is. I'm a straight cow (moo moo), so I would like to get creative with what I will make. I fs want to try making cheese and butter. And then I think I will dehydrate anything else to be used for milk baths for my Psoriasis. The question is, how long can j store it for these things. Making cheese and butter takes quite a bit of milk. So at the very least I will need a couple/few days to make enough to really work with. Does it keep that long? Like if I kept it in a pitcher in the fridge or something?