If you've already been in a relationship with someone for more than a few dates, the best predictor of the relationship's future is the relationship's present and past. All astrology can do is confirm what you already know, or explain in the language of astrology why it's going the way it is. Synastry isn't a magic tool that makes a relationship succeed or fail. Your choices, and the other person's choices, do that.
It sounds like you've been together for a while. If it's not a stable relationship now, it's not likely to be in the future, no matter what your synastry shows.
Thanks Osamenor. His act is so weird and ignores me after the argument. Actually I didn't know anything about astrology during time I dated him, I only started to learn it when I was curious to determine his behavior. Read from online mentions Pluto energy is very powerful.....anyway I guess it's a just cookbook astrology of general idea.
Sun Conjunct Pluto
The conjunction of composite Sun and Pluto signifies that this relationship will have very deep and long-lasting effects on you.
This aspect will work in one of two ways. The first possibility is that your relationship will have a very powerful effect on other people. Use that power carefully, because if it is misused, others join together to put you down.
The second possibility is that the relationship will have a powerful internal effect and cause you both to go through important changes and transformations.
One warning, particularly for love relationships and marriages! At times you both will feel that everything is collapsing and that the whole relationship is over. With a strong Pluto, this may simply mean the beginning of a major change; when it is complete you may enter a new phase that will be better than ever for both of you. Try to be patient when such crises occur.