This can take some practice, just like building any skill, but, if you stick with it, you will have a great coping skill.

Here are steps for an effective visualization:

1. Start by going to a place that is quiet and where you will not be disturbed for 15 minutes or so.
2. Get in a comfortable position. Close your eyes if you like.
3. Take some deep, slow breaths. Breathe in through your nose, out through your mouth.
4. Think of someplace you have been (or imagined / or seen in a movie) that is very pleasant, calm, soothing.
5. Reconnect with all your sensory memories attached to this place. What do you see? Hear? Feel / Touch? Smell? Taste? The more detailed you can be, the more real it will seem. For example, if you are at the beach, what color is the water? Are the waves gently lapping the shore, or are they big, rolling waves? Is there a rhythm to the sound of the waves? What is the temperature? What do you smell? Maybe salty ocean air or tropical scents. What do you taste?
6. Keep taking slow, deep breaths.

If your mind drifts away from your happy place, just tell yourself you are going back for a few more minutes.