Take a step back. This is MMM forum, I am happy to give advice on your career but can't overlook the two car loans you just mentioned. You need to read this once a day until you get rid of those car loans:
http://www.mrmoneymustache.com/2012/04/18/news-flash-your-debt-is-an-emergency/With the income you guys have, just buckle down and live on rice and beans for a while. (obviously you can eat well cheaply, the "rice and beans" is figurative, no eating out, no drinking out, no movies, etc, etc - the link above spells it out) Pick a vehicle to start with, probably yours. Pay it down until you can sell it, and then buy a $3500 high mpg car to use while you change your life around to financially sound. Repeat with other car, and really try to live where you can only use one car, that would be a huge savings. With the car payments out of the way you will have done two things. You will be in a better financial position to make career changes or go back to school, and more importantly you will have exercised and strengthened your badassity muscle!
With all debt removed, spend some time researching your options. Police work might be a great extension of your current career, how much more school would you need, how much would it cost, how easy to get in, where to get a job when you get out, how much does it pay, how happy are those who have that job, etc. Repeat for other career options and make lots of pros/cons lists. You have lots of time while paying off your debt, so by the time your debt is gone you can make that move and start into your new career. You see first hand what debt does if taken out without good plans, the school debt your gf has is a good education for you. Don't repeat that mistake, be wise with any new debt you take and and try to finish whatever new degree you need while working. Starting a new career without new debt is certainly possible.
You have a good paying job, don't make any rash move career wise until you solidify your financial situation. You could FI on your current salary, so don't assume you need a ton more to have a great life. The question is what you want to do with your life, not how much more money you can make.