I use 505 basting spray instead of pins...it works so much better...only 505, though...I found a great video (4 part series) about it, and it also includes all aspects of machine quilting. Its on youtube, here is the link:
http://www.youtube.com/watch?v=39I5A3iyCtw
I know it says for free motion quilting, but it is such a great video series in general that it works for stitch in the ditch, too... I have also had so much frustration, and can only say to keep trying! Do google searches, and get all the information you can...this board has great advice, too...as we all know...I also used the following video to make the home made table that helps hold the weight of the quilt, and you make it so your machine will fit down in it...here is that link:
http://www.youtube.com/watch?v=g14go...feature=relmfu
I also don't do exactly stitch in the ditch, I stitch about 1/8" away, as I think it just looks nicer, and it can be really hard to stay right in that ditch!
Good luck to you, and please know that it can be done. I really hope you won't give up on it...as your quilt is beautiful!! And if you can piece that, you can quilt it...I am sure it is not as easy to do it on the domestic machines, but I also have several gals in my quilting group that also quilt on their domestics...I really debated sending my 1st one out to be done on the long-arm..but, I really wanted my quilts to be done by me...the whole thing...Lastly if it turns out to be something that just is not going to work on the machine...I hand quilt it!! :-)
Regards,
Kif