You gotta read the book. Make it a priority, make time to read it.
First, the book is totally pro-marriage. I don't know the answer to "why are you still married", only you do, but you are right that the spark could return.
Second, you are not using a solution focused approach. This fights are not getting anything accomplished.
The book will help you consider some alternatives to knock down, drag out, screaming matches. Things that could actually HELP!!
Me: 35 Her (WAW): 34 D8, S5, D2 T:16, M:9 BD + D: 4/3/2015 EA Confirmed 5/6/2015 Separation under the same roof