Career Change from Graphic Design to Interior Design

Hello all,

I am contemplating a career change from graphic design to interior design. Interior design has always been a passion of mine, I majored in graphic design because I had more experience with it. Looking back, I wish I had chosen differently! Does anyone have any recommendations on how to make the career jump? I've been working about 3 1/2 years now, and know that I will most likely have to start off in a assistant role, which is fine. I have my BS in Graphic Design, would I want to focus on getting a Masters in Interior Design? It seems kinda redundant to get another bachelors. Would I have to wait until I got the masters to pursue a job? Any help would be appreciated. Thanks!