I don't think your quilting is cursed. I mean, I could see if you said, "I gave someone a quilt, and the next day, they did X." And that happened 5 times in a row.
What you're describing doesn't have anything to do with the quilts - things are happening months & years later! The underlying issue seems to be the people in your life, who just so happen to have been recipients of your quilts.
So... stop making quilts for people who don't deserve them. As to the rest... I think other people have said lots. :)
ebony