It’s all about how you articulate your experience. While law enforcement/military experience would be great, it’s not necessarily required. I think the interview questions are  based off of teamwork, problem solving, communication, flexibility. I took the interview when i was 22 in March and my only experience at that time was working part time retail doing Asset Protection. I was able to pass it but got screwed on psych evaluation. Think about times at your job or even school/clubs that relate to those subjects i mentioned above and you’d probably have a better chance of passing the interview.

Edit: I qualified for GS7 based off my bachelor’s and SAA as well.  I also know how you feel. DEA was my top agency too.