Or at least almost fixed. My tension on my Voyager 17 is so much better, it actually sews now! I broke down and took the tension assembly apart again, cleaned it well, and reinserted it. Then the bobbin race, and a new bobbin case. It isn't perfect, but is so very much better. I'm not afraid to attempt an actual top instead of just practice pieces now.
Thanks for all the suggestions (and letting me vent) everyone, you all are great.