Oh dear your baby is under the weather :( , might be your thread, did you tried using your regular thread again to see if it still does that? If you did and it still does that, when was the last time you had your machine serviced?? Also make sure that both the top and the bobbin threads are the same. Try not to mess with the tensions because it will be hard to get it back to the way they need to be.
If you have checked all the normal things like the thread, the needle,the bobbin is filled nice and tight, you checked there is no dust bunnies under where the bobbin goes and your tensions are where they need to be and is still acting up then your baby needs to see the doctor. :( :shock: :cry: :roll: :?