Competitive placement OW2

Hey, Im master 5 and i won 4 games and lost 4 or 5 and im still master 5 and didnt finish the 3 win games left. My question is will i get the master rewards in the end of the season if i stopped at what i am at?
Also i noticed my last comp matches i played with diamond players so does that mean ill get demoted to diamond if i finish the 3 games left?

With a record like that, you should be fine. If you were like 0-5, then the game would update your rank accordingly at the end of the season.