Meditating takes time and practice. While relaxation is a key point in meditation, trying to be relaxed may cause exactly the opposite (Like if I tell you to not think about an elephant, it causes you to think about an elephant). Also, meditation isn't really about "shutting your mind off." It's about not letting your thoughts become a distraction. I would suggest you just try meditation, and instead of focusing on relaxing or quieting your mind, just focus on your breathing. After a while, you may notice that your mind has been quieted, and you are more relaxed. Just keepin mind that this still take practice.
I have done past life readings with my Tarot cards before. You could find someone who would be willing to give you such a reading, or if you're up to it, you could learn tarot yourself and try it.