What am I supposed to be doing?

My 3s record before my losing streak a couple days ago was around 26-10. Since then, I'm not sitting at 27-30. 72% winrate toppled over to 47% and it's honestly probably gonna be sinking further. I don't know what's been going on but quite frankly I'm tired of it. This is my favorite game mode and I can't even play it without getting frustrated.

What is the deal with matchmaking here? Most of the champs I was on my winstreak with, I'm still using. All of what I used to do, I'm still doing. In so many of my games I'm leading in gold, CS, damage, kills, etc., on my team, but it amounts to nothing. This is happening game after game after game, and I'm getting way too drained. I don't mind losing if I deserve to lose, but if I have to lose so often, in this manner, then why am I even playing anymore? What am I supposed to be doing?

This has been my favorite season as far as runes and everything so far, and for a while I was having way more fun then I'd ever had with the game before. Every time I'd load it up before it was because I wanted to have some fun and play, win or lose. Now I load it up just hoping that I'm not going to be tanking my winrate even further. Check my norms winrate on op.gg and you'll see I'm at frickin' 16%, when just before this streak I was able to maintain 55% or higher.

It's not fun anymore. Maybe my first game is, sure, but after that, nah.

EDIT: Another two games after I make this post and both losses. Yeah, I give up.

EDIT 2: And a third game in a different game mode and it happens once again. I'm done with the game for a long while.