Ranked Game Points Please Expalin

I won 4 games in a row then lost one and noticed I lost 20 points for one lousy loss and only gain 13 points for a win. WTF!!!!!!!!!! I was Silver 1 back in Season 2 then quit playing for a couple years. When I came back I tried to help out some newbies, but didn't know they were creating ranked games and I was in my placement series. Omg I was mortified when I was viewing my profile to set up some new strategies and came across the league page and saw I was in my 5th placement match. I was so pissed! Now I'm finding it harder than ever to climb up. So many noobs, and they don't listen when you tell them "DON'T FOCUS THE TANKS!" and other stuff.. I'm miserable