While you can control your weight to a certain extent, your height is another story. The good news is that not all models are tall and thin. If you're shorter than 5 feet 5, consider modeling petite clothing. If you have a medium-to-large build, consider modeling plus-size clothing. You could also model items like shoes, makeup, or jewelry. In these fields, agents and scouts focus on specific parts of your body like your hands or feet. Even if things do work out, you'll likely need something to fall back on by your mid-20s. Don't wait until you need to make new plans. Start studying while you're modeling or looking for modeling gigs. If you're traveling for work, talk to an academic adviser about online courses. Modeling isn't the only career in the fashion industry. With a BA in journalism, you can write for a fashion magazine. A BFA in photography and an impressive portfolio could land you a really nice living as a fashion photographer. If you have a knack for figure drawing and fiber arts like sewing, you should think about becoming a fashion designer.

Summary:
Consider other paths in modeling. Go to college. Consider other fashion-related careers.