Dream about swimming with giant fish stands for loss of vitality, loss of faith in yourself and lack of self-confidence. You need to break down your problems into pieces you can handle. Someone else is trying to reap your rewards. The dream is a clue for your feelings of shame and guilt. Your own self-image may have suffered and taken some blow.
Swimming with giant fish dream is unfortunately a warning alert for your pent up frustrations and anger. You are experiencing anxieties about fitting in or being suited for some position or role. You are feeling suffocated or smothered by a situation in your life. This suggests grief, bad luck and unhappiness. You are utilizing deception and underhanded means to get what you want.
If you dreamt about swimming with giant fish:
You realize that various duties have meant that you could not be with them as much as you would like, and are willing to do what it takes to restore a sense of balance and harmony. Good for you!