Yes you are correct Navamsha chart or the D9 chart is very important for marriage and it should be read for marriage and knowing the life partner. Looking at your navamsha chart we see that the 7th house is in the Rahu and Ketu axis , which is not good. Moon which is the 7th lord in your D1 chart gets debilitated in the D9 chart or the Navamsha chart. This again is not good. The conjunction of 7th lord Mars with Saturn is never good and it is in the 4th house of D1 chart and 7th house from Moon.
Therefore there is no denying that your horoscope is very weak on the marriage front. However if a person tries, there is nothing that he / she cannot achieve. I suggest that you should try and you will get towards your goals.