Sorry to hear of your frustration. I sure would not use Bottom line in the top and bottom with a 14 needle. That thread on top is way to fine for that large of a needle. Give it a try with nothing finer than wt. I also would increase the top tension.
Saw your blog---your quilts are beautiful; can tell that you are no amateur. I would never use bottom line on the top; however, I really like thick threads on top like 28 wt. Keep on trying. Good luck!