I'll be serious:

when do the globle economics crisis ends?
NEVER! This is not an exception. This is normal.

This time, we are going so low because we went up quickly, and to record highs.

do this rises more near future?
Maybe, nobody could know how high or low it gets.

how long it will run?
It's usually an 8-11 year cycle, see the link above.

how is qatar affected by economic crisis ?
Just like any other country. Fortunately, we don't have real industries, so we have only been affected by energy prices sinking to new lows (We went back to 2004 prices).

do qatar suffers badly more near future?
Maybe.