Just like your body, your mind can get tired, so you need mental relaxation. You may not even be aware of it, but thinking, worrying, and all the things that go on in the back of your mind can get it exhausted. When that happens, it's time to take a break and do something to rest your mind. You should set aside time every day for mental relaxation, and there are several ways you can do this.

Try a meditation breathing exercise. Sit relaxed in a quiet place and clear your mind. Just focus on your breath coming in and going out of your body. Don't think about anything else but your breath, and don't try to control your breath. Just let your body breathe naturally. Try to sit for as long as you can, at least five minutes. You'll find that afterwards your mind is calmer and your body more relaxed.

Empty your mind. Lie flat on a soft but firm surface and close your eyes. Imagine a small black dot. Slowly increase the size of the dot until it fills your mind's eye. All you see is black. Stay with that blackness for as long as you can. It may be difficult at first, but with practice you'll be able to train yourself to keep out any thoughts except the black. This gives your mind a chance to be empty and rejuvenate.

Try hypnosis for mental relaxation and see what it can do for you.