I just got a terrible tarot reading and I need help understanding it.?

I'm in a very happy relationship with someone I trust very much. This person has never lied to me or cheated on me that I know of. But, today I had a tarot card reading done that revealed that someone very close to me would deceive me and it would be someone I would never think would hurt me. The entire tarot reading discussed issues such as deceit and betrayal but said it wouldn't be in the way that I thought it would be. I got probably some of the worst cards in the deck such as The Devil Card...The Tower Card..The Ten of Swords...a lot of cards dealing with strife and arguing. I was really worried before I had the tarot reading done that it would end up bad..just because that's my luck. So I'm wondering is it possible to imprint negative feelings on a tarot card reading? If not, how often are tarot card readings true and are their other possible meanings for some of the cards I mentioned?