I couldn't live without my two (2) Brother sewing machines!! I love the ease of threading, the wealth of stitches, and the price has been more than reasonable. I have an ES2000 and then bought a C6000.
I checked my book on thread breaking... check the tension!!! you might have set the tension way above 3 or 4 just in threading it. You might have a needle in the machine that is too small... There might be a tangle under the bobbin in the bobbin case...
I hope I helped.
Anita