what is the meaning of the phrase
1) comes down upon you sharp
2) sat flat down

answer fast..

The correct meaning of the given phrases would be better explained if the context was given.
'To come down on' means to reprimand or scold, or oppose.
'To come down upon you sharp' might mean land on you suddenly, or oppose you sharply.

'Sat flat down' means to sit down flat on the ground.