The nine of swords is a card that symbolizes doubt and issues. Usually when someone has nightmares, it is because their mind is focused on a certain negative aspect of their life. You are thinking about it too much and getting too stressed out about it, and letting it seep into the world of dreams and affect your subconscious. These nightmares are nature's way of letting you know that you need to relax on the level of anxiety you are feeling, or these issues will become worse.
It is a common idea that worrying never gets you anywhere and it is just as true for the romantic area of your life as it is for any other area. When your mind hovers over the idea that your lover might be cheating on you or you are suspicious of them for some other reason, then this will rest heavily on your mind and it will ruin you. No matter how doubtful you are, the best and most healthy thing you can do is continue to trust them, or confront the issue immediately. Waiting over it will only make you sicker.
When this card is applied to your financial future it usually means you are having a lot of money worries. You are struggling with all of the debts that you owe and do not know how you are going to climb out of your mountain of debt. However, when all you can do is think about money worries, it just makes things worse. Your mind will become too plagued down by various stresses for you to be productive at all. In order for you to rise above your problems you need a clear head, and worrying will not help you here.
When the nine of swords appears in the area of your fortune that deals with your career, this means you have had too many responsibilities thrust on you. You are not sure whether you can complete all of the work that you've been given, but you have to because it is what you are paid to do. In order to rise above this adversity, you need to complete the work despite whatever misgivings you may have. Once you get down working in the first place, it will seem as if the difficulty is near insurmountable. But you will be able to get past it as long as you ignore the stress.
When the nine of swords appears in the area of the tarot spread that deals with health and happiness, this usually means that you are so overcome with stress and worries and doubt that it is beginning to affect your physical health. This is possible as your mental abilities apply directly to your physical abilities. It will be hard to work through but not impossible. You just need to try to be a less stressed person and in the end things will work out better for you.