Changing Careers from Accounting (US ed) to Finance - I'm Mildly Terrified

So, I have made my decision to transition from accounting with less than a year of work experience to finance. I went to a target school in US, but graduated with a BS in Accounting. Admittedly, I did not know much about career opportunities when I first entered my business school, but I knew I wanted to do something quantitative.

Finance intrigued me at first, but I did not think highly of several of my colleagues who thought that a career in finance will make them gods (I'm exaggerating, but they acted like they were more important than everyone else). I liked to fit in the accounting crowd, but I thought the subject was too easy in the sense that there were no "moving" parts and it was just following rules and GAAP regulations; it seemed as if you could ace every accounting exam through sheer practice and effort, with no analytical skill involved.

Of course, after I graduated, I missed my chance of entering finance from an undergrad program, but I recently went to my alumni career fair and found a bridge program that will send me to London for a year long internship. I don't get to go to London until I get interview and get placed into a host firm.

The purpose of my post is that I have no clue how to approach finance interviews, nor do I know much about the finance field. I can only mention that I f*****g love Excel and I can create a custom tables of varying complexities for my needs using every formula in my arsenal. I think I need some advice from anyone working in finance about realistic expectations and maybe some encouragement to help me through this process.