Try to stay focused on the long term benefits of eating healthy. I know all to well the want to eat something for comfort or because you just don't want to have to think or worry about it for that moment. In the end though it ends the same, you'll feel guilty, and when you dream about being thinner, you'll regret that you didn't start earlier. Plus think of the extra confidence you'll have when you start teaching.
Speaking of which. I live in VA and have my BS. I looked into the Teach in Virginia program. It allows you to teach without a certification at high need schools. You have to complete your certification within 3 years of teaching. There is also here a Career Switcher Program, that requires you to attend classes for 6 months, then you get to teach. During the first year of teaching you attend seminars, and become certified. Only downside is you have to have 5 years work experience.
I considered switching careers, but I wasn't ready to leave my current one. I wanted to teach Elementary school. My kids are 3 and 4, so the thought of working full time and attending classes, is just not something I can commit to right now.