Stick with it, been there and done that! I cut one of my quilts once because there was fold underneath when I was trimming ready to bind and I nicked a perfect arrow shaped point through all layers about 1". I panicked initially so left the room, walked outside in the garden and came up with the solution. I used Bondaweb, stuck each layer together the zig-zagged with invisible thread. It worked, because I had real trouble trying to find the repair. Boy was I relieved. lesson well learned. Now I am extra, extra careful. Hope you get yours sorted, I do empathise with you. Good luck.