You're beautiful, and have a lovely figure, but your port is rather boring.....and you've got an uncomfortable expression or posture in almost all of your images.
Get a couple of killer outfits together, find a neat location to shoot in, be willing to drive, do your own makeup, or hire a MUA, and then contact photographers you want to shoot with and pitch them your idea (TF). Before any shoot, practice your expressions and poses in front of the mirror, and find your best angles in the outfits you'll be using.
Replying to castings is a very indirect way to try and get photographers to work with you. Since what you're doing isn't working, try being more direct. Send pm's, and I think you'll have a lot more luck. If you do some TF and build a better port, then you should also start booking more paid work.