I have trouble with the habit that says to darken my room! I am very scared in the dark but I want to achieve my habit, what should I do?

The challenge is to make your room darker which does not have to mean to make it completely dark. If you use during the evening normal lights, try to use some smaller table lights before going to sleep to complete the routine. Or if you use a small light during the day already, try using something even more dimmer (f.e. I have a globe that can be turned on but the light that it emits is only a little).