Guild Wars 2

As the title says, I’m looking for some information about how the system works so I can better understand what’s going on in my pvp life. Skip ahead to the questions if you don’t want my background info.

Background:
I started the season off really strong with an end total of 7 wins out of my 10 placements putting me about 8 points under plat division. Pretty solid start so I was excited to get going and decided to continue playing matches but I noticed that my matches seemed of lower quality. I assumed it was just luck of the draw and kept going but it started to become a trend that I ended up with teams lacking rotational knowledge or combat skills fighting against against teams of 2 man esl players or 2 groups of 2 esl players. So I gave it my best in those matches and got done what I could and I’d end with 2 or 3 of the top stats each match and actually a fairly solid game played but then I’d see my rating drop anywhere from 20 to 36 points. No biggie it’s just a few matches, I’ll win it right back right? No, wins where I performed better than the losses gave me 9 rating points and were followed immediately by the same caliber of losses. Got me to thinking if it’s an issue with me and if duoing would help. So I polished up on my rotations and combat and actively tried to make sure I was doing the best but still the same result, got a duo buddy who plays extremely well and still the same result so then I came here to see if people could help me to figure out what’s going on and help me fix it so I can achieve at the level I want to.

Questions:
1) Why the sudden decrease in match quality? Is it from others doing their placement matches? Not a big enough pool of players yet?

2) Why do I receive such large deductions in rating for very close losses or losses where I played very well yet small additions for doing even better on wins?

3) What could I do as a player to improve my match quality?

4) Are there any general tips you guys can give me to focus on that you think could help me in future matches to give my team a better fighting chance?

Thanks in advance for all your answers, good luck to the rest of you this season.