I notice in your post that you do not qualify what you are doing to practice-only that you have made lots of sandwiches (to fill a dumpster). Are you trying to just draw or doodle with your needle? Do you draw a design and try to follow it? Learning to machine quilt is a progressive activity in your practice. Consider a book such as Harriet Hargrave's book on machine quilting or a craftsy class. Leah Day receives great reviews for her free motion class. How about a class at a local LQS? Please don't give up but structure your practice to move forward in your pursuit of quilting.