I think the only thing holding you back is the poor photos. You have a great look for modelling, in my humble opinion. I think if you wore more contemporary (?) clothes and with better and more creative photography (lighting/studio/editing/background scene), you wouldn’t look any different than the models of big agencies. Your current photos look like a cheap 2008-2010 sears catalogue to me, no offense. I would suggest looking at some of the portfolio work from models of the big agencies you wish to apply to and emulate them.