Modeling underwear and lingerie should not only be a glamour thing in your portfolio.You should also market yourself for catalog work. In a print and lifestyle and commercial way. Commercial print modeling is best for petite and shorter girls to consider to pursue but this does not mean an itchy sweater, but there is a fine line between slutty and working as a real model. You should consider posing in ways that look like a lingerie catalog, not just in Maxim style. You will have better luck with agents if you pose in ways that make you look like you are selling a product, working with a brand, and actually modeling something.
An agent will like that too. Commercial print modeling agencies want to see that you can "work" a product. Not just yourself.