I know this can be very confusing but actually the answer to your question as to whether your ex is really you or him is that he is both in your dream.
I see the dream as telling you that when you are thinking about your ex, you may be perceiving that he is very sad, but somehow cannot allow yourself to retain this thought. When you cannot let yourself think that it is possible that he does feel some sadness, you are actually enabling him to deny his own feelings – feelings he does not want to have.
This is based upon the spiritual/psychological make up of a husband-wife union. Married people are joined not only “in the flesh” but on a mental-spiritual level as well. Just separating the two partners does not sever this connection – only death of one partner does this.