Someone made the remark that it looks like you took a deeper seam towards the middle to keep it from bulging. I agree. If you look closely, the left side matches at the intersection of the first diamond, but by the second diamond, the diamonds don't match. By the time you get to the white in the middle, most if those diamonds on the left have been sewn into the seam. Hopefully you haven't trimmed the seams. It really shouldn't be to difficult to repair, just a bit tedious. If you have paper that has a grid, I would suggest using that as a foundation as if you were paper piecing for one half of the star, easing into square if it has been stretched. If you don't want to go that route, you might consider stabilizing the seam with a seam just to the right of where you want the final seam to be with a regular size stitch...not a basting stitch..carefully feeding the fabric so it doesn't stretch anymore. Once one side is solid, carefully match up the intersecting seams with pins as suggested earlier. One other thing I've learned, stitch from the center out. Since you love the fabric, you will treasure the quilt when you get it to the point that you like the results. It doesn't have to be perfect, just loved.!