How can I decide what to master in college?

Theres not alot of option in Oklahoma unless I want to be a welder or a nurse. And neither are of enough interest for me to pursue a life long career in. I've considered web development, which is a promising hire rate but I can see will become boring mundane, eye straining job or getting a psychology degree, which holds great interest but holds little promise in hiring. Plus I need to stick to classes I can only do online because I am a stay-at-home-mom. I'm doing this because I need to make enough income to put food on the table, put my child into daycare, and pay of my life-limiting credit so I can move us into a house. Is there anywhere I can take a career test? I will contact a counselor soon, but Im hoping I can make some decisions before he asks me what they are.