7th house is the house of spouse and 8th house is the family of the spouse. If you understand astrology you should know this. Now when 7th lord goes into the 8th house, it means that the inclination of the spouse is very much towards his/her family. You know girl or boys where they leave all decisions to the family.
When Venus is combust meaning it is conjoined with Sun, it is not good for marriage. In a horoscope it lessens the marital happiness and in a boys horoscope it means that his wife will be sick and have health issues.