i don't know if you're too sensitive in your overall life and personality, but you are certainly too sensitive for this job with this boss.
but take heart. it's fixable.
you had a great review and got a raise, so you know that your work is good and that she has professional regard for you, even if she doesn't express it well.
she clearly doesn't handle stress well or understand how to give instruction, direction and correction to a subordinate. but you can give HER instruction on how to treat you by how you respond.
a great response to her snappy comment over the costume sizing would have been a calm, 'you have a different perspective because this is old hat to you and it's all new to me. if i'm not doing it correctly it's because i need more training, not because i'm stupid. i look forward to us taking the time to go over this thoroughly so we're both confident that i understand it completely.'
90% of the time something like this will rein in the blunt force of a tactless personality and get them to re-evaluate (even if they don't admit it.) and what you want is better treatment, not an apology, right?
practice. give yourself a series of scenarios in which she has treated you poorly and think of better responses. use a mirror, or your bestie. i think you'll be very surprised at how much better your boss interacts with you when you push back courteously but firmly.
and if it doesn't work? she's just a cow and you need a different job.
but i think this is a situation that is custom made to help YOU be more assertive and raise the bar for how you allow yourself to be treated overall, not just with her.
go get her!
khairete
S.