cayenneman What blackbetty61 says about the binders is true, it is the best thing to add to help prevent fatting out. The Sure Gel and the Soy Protein Blend both speed up and help with protein extraction as they are adding more protein to the mix and they are designed to “gum up” and bind things together. The Carrot Fiber doesn’t add any protein but it can hold up to 26 times its weight in water so it does a great job in keeping your sausage moist. The Super Bind is a blend of Carrot Fiber and Potato Starch. It gives you the water holding ability of the carrot and the potato starch turns into a gel at just about the same temperature as meat will start to expel its water, so it absorbs all of that and keeps it in the sausage.
Ingredients of the seasoning absolutely play a role in forming the consistency of the sausage, this is especially true of salt content. If you are looking to firm up your sausage my first recommendation would be to follow deplorablenc1’s advice and go with a pre-packaged seasoning. However, if you want to keep using your homemade recipe then I would use either Super Bind or Sure Gel, the Super Bind is a little more expensive than the other binders but it is worth it when trying to correct a problem.
Post pics when it is done!