The chart shows everything. Low self esteem is something that seems to plague some people much worse than others. One can look to the chart and see why. I will try to address some of the placements I have seen in charts of people who suffer from low self esteem.
Saturn is classic for throwing cold water on anything it touches. If it touches your Moon, you will be insecure about your feelings. One’s feelings are the deepest part of one.Hence, Moon/Saturn makes one insecure about one’s very being. If Saturn touches one’s Sun, one will doubt one’s ego and identity. Saturn/Sun will show up more in the work life of the native, rather than the emotional life whcih is the purview of the Moon. Saturn /Sun would be classic of the man who can’t seem to be successful in work. He can’t seem to move to the top of the company. If he advances, he sabotages himself. He feels like a loser, so he designs life so he will lose in his career and social standing.