Can you recommend a good relaxation technique?

Use your imagination: Let yourself remember a beautiful place in nature that you've been to while on vacation, close your eyes and pretend you are there. Do this anywhere except while driving or operating heavy machinery. :).

Go to a quiet room: Go to a quiet room with dimmed lights. Sit in a comfortable chair. Imagine you are in a pleasant and safe place.See all the details of your place in you head. See if you can smell any fragrances. Breathe deeply and slowly while counting your breaths, 1 when you breathe in and 2 when you breathe out. Just use 1 and 2. Do this once per day, only 10 minutes at first, then add more time later.