Some people have mental blocks and allow it to happen. sometimes it happens because ultimately, the person learns from it.
If you want to protect yourself, learn to use your energy as a shield. The simplest shield is affirming and knowing you're safe. If you want to go into more detailed constructs of energy, you're welcome to do that as well.
Theoretically, I would say that a Tarot card can be used on you, but that is by far not what it's supposed to be used for. Tarot is a tool of divination, the ability to learn the past, present, and future by psychic means. Perhaps you could learn Tarot if you wanted to. Learn the energies you feel are being used to influence your life. If you have a better understanding, you'll come out of it better. However, it is up to you. :)