WTF – what a total douche bag boss.
Do you have it in writing that you would be paid $9 an hour? If so you need to go after the rest of your money. You said it is a small business, how small? If it is less than 50 employees (in some states) they can try to fight and say giving you breaks causes hardship for the business. So you need to look into your states laws about this. They also do not have to pay you for the time you are pumping. It sounds like your boss sucks and overall it would be in your best interest to find another job with a better boss.
A contract is a contract, if you signed to be paid $9, she can’t just adjust ur pay to 8.5$ without making u sign another document with the new amount. Is there an individual who manages HR or is she the one that does that?