ANSWER - The nine of swords is generally a bit of a portent of doom card but it can also indicate an obsession or a reluctance to give something up. I wonder if perhaps in your case the recurrence of the card suggests that you are placing too much emphasis on the idea that you are being lied to. The trouble with dwelling on such a concept can lead to mild paranoia and uncertainty and probably isn't the best head space to involve yourself in.
The short answer is - yes you can use the Tarot to narrow down who is lying to you. If you ask the right questions you can ascertain whether male or female and the general age of the person. The cards will easily yield this information. However I am unsure if this would help you very much. At any stage of your life probably 90% of those you know are lying to you or deceiving you in some way, they will have their own motives for doing so and likely their intention is not to hurt you - lying is unfortunately just human nature.
In truth, the Tarot is used best when it doesn't deal in absolutes. My advice would be to keep the warning in your mind as general guidance but not to let it dominate your thoughts.
Remember that the cards foretell a possible outcome, not an inevitable outcome. Tarot guidance is a good way to keep yourself aware of the possibilities of your present and your future but don't let yourself get bogged down too much trying to use it to predict every incident in your life. Just keep an eye out and decide for yourself who is speaking the truth to you.