Why do parents fight?
Parents fight for many different reasons. They may fight because they lose their ability to communicate. Most of the time there are issues that don't get solved and they spill over into new issues. They basically have a failure to communicate and they are hearing each other but not listening.
Sometimes, when you love a person so much, you fight because you are too much alike.
Don't let yourself think that you are responsible for any of it. With the economy being the way it is right now, everyone has money problems. Aside from this they both love you, although it can be hard to believe.