You can learn to control your experiences by keeping a psychic journal. Every time you get one of these feelings of dread, or sensations of people's past, write it down in as much detail as possible. Also, learn how to meditate and see if you get any clear messages when you do so. Again, afterward, write it all down. In this way you will become more familiar with the feelings, you'll see patterns and will eventually be able to control your gift.