Problem solving is something that I love

Hi Lauren, 
Thanks for writing. It's great that you've gotten some experience and have some good footing to make your next career move. I started as a Bio major as well, and then transferred into env engineering. I'd say school-wise, the difference was math and mechanics (more of that in engineering vs. the natural sciences), and career-wise, I'd say scientists and engineers work hand in hand together all the time and are both equally involved with problem solving. They each simply have some different "tools" in their toolboxes to get the job done.

Before going back to school, I would consider trying your hand at applying for some of the jobs you seek with your current degree and experience. If you can get the job through a lateral career move (no promotion or raise) without another degree, you just saved yourself a lot of time and money! You'd be surprised how flexible employers can be for eager people who are smart and willing to solve problems. That way, you get paid to build your own toolbox, and get even more leverage for your next move. 

Good luck!
Molly