career change from academic researcher to IBD

hi

I'm currently working in Tokyo, as a political economy researcher, for 3years.

I recently realised, conducting research is not my thing (like: doubt and scepticism about what I am doing, highly worried about my future, what if I cannot get into tenured or produce any great quality of dissertation, what should I do). 

I look for a career change. But, I know my majors (politics, international relations, economics, and quantitative methods (mostly data analysis)) are not related to any finance and account fields. Even if I studied economics, it would not impact the career change to be IBD worker. Thus, I consider applying for a business master's degree and am really interested in Zicklin's Quantitative Method & Modeling (which is what I used to do and like it). 

SO, Could anyone recommend me or tell me a story about how to change career and set in IB. I would like to listen to different perspectives.  

Where I studied

Glasgow University (MA) Politics and Economics 

University College London (MSc) Social Research Methods