Imagination is very powerful. When you imagine a peaceful situation, your mind becomes peaceful. On the other hand, you can scare yourself to death by imagining terrible situations. Since you have a choice, choose peaceful images, like sitting in meditation near the Buddha in a peaceful setting. Imagine all the details. Imagine that you are deep in the mountains. Cool, quiet. Near the Buddha you feel very calm, tranquil, safe, secure, and free from dirt. Or collect some poems which make your mind calm. Copy them neatly in a small notebook, which you can carry with you.