Even though you have put a lot of time and probably $$$ for the fabric into it I don't think you will ever be happy with any patch job. Anything you do will will probably take more time that could be spent on a new one. I think I would set it aside and maybe pull it out later and use the good parts for some small project-a table runner,placemats etc. This fabric looks like it frayed way, way too much. If you got it at a good shop I would tkae it in and show it to them and maybe they will offer you something else or a discount on you next purchase. Good luck!