This is the meaning of 12th house placements inthe composite chart:Basically, the twelfth house represents repressed thoughts. It signifies once-conscious ideas that have been eliminated from the waking mind because the mind has chosen not to deal with them.
The problem with repressed ideas ist that they give rise to unconsciously motivated actions that are often harmful to an individual or to a relationship. Even when a couple makes a great effort to deal with problems consciously and openly, there is often a lot going on that is raw, intimate and heavily psychological.
But there are those who benefit greatly from intense, day-to-day psychological encounters. And there are individuals whose unconscious actions dovetail with their partner's so perfectly well that they are indispensable to each other.
Also you said you hace the sun in 1st house.This is what can be said regarding that:
The first house describes the impression the relationship gives rather than what it really is. A strong first house can be an indication of a relationship that is all show and no substance. Nevertheless, a strong first house is usually a sign of a significant relationship that will have a great impact on the lives of those involved. These relationships tend to be important ones.
I personally feel it's nice to have so many planets in the 12th house and also the sun in the first. i guess you people can understand each other really well if you try to ...there is a potential for a strong relationship.But that's what i feel.