I doubt if your quilt would fall apart, but yes, it sounds like your tension is off a bit. You should not see top thread on the bottom or bobbin thread on the top. Usually, you just tighten (or loosen) the top tension. Rarely should you have to change the tension in the bobbin, but a good test is to put your bobbin in the bobbin case, and hang it by holding the thread. It should hang without unwinding, but if you shake the thread it should pull out some. If it unthreads freely when hanging, it's too loose (tighten the little screw) and if it doesn't pull out at all when you shake it, then it's too tight. Hope that helps!