Read my blog Navagraha Astrology online and post your birth details if you are interested in your answers. Your statements are through insufficient knowledge in astrology based on which we cannot give you answers. Obviously you have learned astrology from quacks in the field.
For Dhanur(Sagittarius) lagna,seventh is
badhaka house.Seventh house is Midhuna(Gemini).
The remedy is to do penance for one year.
Penance means doing fast for one day in a week.
On the day of fast,you can eat uncooked vegetables. firstname.lastname@example.org