You need to find a happy medium for both tensions top and bottom. And always remember when adjusting tensions to adjust very little, sew to check it, then adjust more as needed. I barely turn my screw for the bottom and barely turn the knob for the top.
Also, have you oiled lately? Have you checked your needle and plate both for burrs? These are all things that can make thread break. What sized needle are you using and thickness of thread? For quilting on a frame I use a titanium blue jeans needle myself because the eye is bigger and I put some oil on a rag and oil the eye of the needle so it runs smooth as well. If you keep breaking top thread, try another spool of thread. Sometimes we can get bad spools. I know I have had a couple in the past. And would bread constantly. Changing the thread almost always worked when I had breakage problems.