The first time I successfully pumped milk, I immediately started imagining myself making a freezer stash. The part of me who feels way better about life if I can plan and prep for any unforeseen circumstance loved the idea of my baby being able to have my custom-made-for-him breast milk, no matter what. I got a bunch of supplies, learned how to freeze, store, and thaw breast milk, then gave up almost instantly afterward. The stash didn’t happen for a lot of reasons, primarily that I'm a mom who hated pumping, with a baby who hated bottles. Fortunately, most moms don't need a freezer full of milk in order to successfully breastfeed, so if you're a new mom seeing those giant stash shots circulating on Facebook and Pinterest, don't freak out and think you're not cut out for the milky mama life.
Also, don't freak out if the first time you thaw your breast milk goes the same way it did for me, and basically everyone else who has ever thawed breast milk ever. Some things inevitably happen the first time you thaw your milk, because handling your own milk that you made and expressed yourself is way different (and more precious) than milk from some other mammal (or soybeans or almonds or whatever). You don't want to waste a drop or ruin its special properties or do anything that could make your baby sick. It's a lot of pressure.
My advice? After all your effort to express your milk, then figuring out how to thaw it, don’t let it go to waste. Make sure whomever is giving the final product to your little one knows how to pace-feed a baby. The last thing you need is for a caregiver to waste that milk by over-feeding your baby (and getting them used to not working to make milk come out in the process). Also, if you end up like me, with a baby who won't take a bottle for more than a few seconds no matter how perfectly it's prepared, there are other ways to feed them if you need to be separated. (My son liked cups and grown-up bottles with straws.) And that precious milk you pumped doesn't need to go to waste if baby ends up not drinking it, either. Turns out, you can use breast milk for lots of things, like skin-soothing milk baths for them (I’d stick to the cosmetic uses, though, and call on a doctor for things like ear infections, no matter what some folks around the web suggest.)
But that's all well in the future, after you get through your first thawing experience. Yes, you'll probably do most or all of the following, and yes, you and your baby will eventually succeed.