How can i get my cat to stop biting and scratching me?

I have an approx 1yr 2mo old female calico cat. Shes healthy and eats regularly with plenty of fresh water. I cant get her to stop biting and scratching me. My fiancee and Roxy (the cat) get along well, but with me shes totally different. Im the main one that takes care of her(feeding her, cleaning her litter, water, etc) and she totally hurts me allllll the time. I pick her up to pet her or she will lay on me and out of nowhere, she will latch on to my hand or arm biting me. Most times she makes small punctures in the top of my hand from biting me because i cant get her to let me go. Another thing is she will follow behind me when i walk through my apartment and put her 2 front paws on the back of my calf and try to scratch me and or bite me. My fiancee and i try to use a squirt bottle of water to get her off counters or tables and it seems to work temporarily. If she bites me to where i cant get her off my hand, i will pop her on the and she will stop. I dont like hiting but thats What works.