Your need to understand that D1 or the natal chart is the primary chart for everything. D9 or the Navamsha chart is important, but if the marriage is not strong in the D1 chart then even if Navamsha chart is good, the marital happiness will not be there. I’m sure you understand as if you reading Navamsha chart, you have knowledge about astrology.
Having said that in your natal chart Mercury rules the 7th house and Mercury is in the 8th house which is not good. 6th lord Sun is in the 7th house. You are also manglik.