I also have been so frustrated while trying to learn FMQ. Tension has never been right...then...I brought 3 of my machines in to be tuned..their normal check ups. When I got them back I wanted to test each one to make sure tension was right (last time I brought them back from repair I didn't test them and discovered 6 months down the road it didn't seem they were ever worked on..bummer..never again!). I started testing by doing FMQ with an early 90's Pfaff. I was excited that the FMQ was better than it ever had been before..straight stitch tension was fine..let me check the next one...an early 90's Bernina. FMQ stitch quality was even better than the Pfaff..., then lastly, check my old Bernina 931 (70's?) and the FMQ stitch quality was BEAUTIFUL!!! I was ecstatic! This is all to say...do you have another machine you can try it on? I even think my old Singer 15-91 might have a fantastic stitch if I could find a darning foot for it. I didn't touch the tension on any of these machines, put the feed dogs down and put stitch length to "0". My thought is perhaps these older mechanical machines are less fussy about tension and might handle FMQ better. It was such a relief for me to know that it wasn't all me...the machine I was working on really had a big part in making this a success. Don't give up! It isn't all a problem with how you are doing it.