Let me ask you a question. Do you have any professional work experience (not counting internships)? I ask this, because, it is really hard to know what you want to do if you haven't done it. I recommend a solid two years of doing something, anything, before going on with the expense of an education. I have seen WAY too many people get to the end and realize they made a mistake. On top of that, the material presented in higher ed programs will be more meaningful to you if you have a frame of reference to relate it to, AND, you could find an employer who offers tuition assistance, which, of course, would be awesome!
I don't say all of this to be mean. It's just you should be sure of your career choice before pursuing a PhD. What exactly is your Master's major? Is there any way it can help you to transition to the newly chosen area? If not, there is no point in staying in it.
I hope this is helpful. I'd like to discuss this further, if you have questions or comments. Getting started in life is not easy!