Keep that state forever

[Precious]

When I read self help materials I feel better, because this is the main reason of this kind of materials, but this state don't last much.I want to make it permanent, a part of me.What I have to do ?

Thanks

[Lonewolf]

Learn a physical anchoring technique to trigger the positive mental state you require. For example, every time you feel really good, click your fingers and concentrate on the good feeling. After a few practice sessions, whenever you click your fingers you will feel good again.
This is a simple explanation, Tony Robbins goes into into in more detail in some of his books.
Also, creating a cycle of heightened (goog) state - productivity - reward - heightened state again is a stable cycle that you could repeat from hour to hour to keep you in flow.
I think it is possible to make this heightened state the basic foundation of your personality although I have not achieved this yet in life.

[Ilya]

In my opinion this happens, because you experience a small shift in your belief system. The things that you would like to be true and achievable for a short while seem true and achievable. But then the everyday routine sucks us back into our usual way of thinking. To make the feeling permament you might need to work on installing new beliefs.
That said, there is no limit to growth and when you reach the higher level of consciousness you will sometimes experience this feel better-feel worse patern, whey you will be getting the first glimpses of the better life.