Ranked anxiety...

I've always hated ranked. It's a stressing flamefest of trolls and afkers, where the system pretty much slaps you in the face when you lose, taking away your LP and saving that loss in your ranked stats forever. Why play ranked then? Well, it's the only queue where matchmaking isn't of a disgustingly poor quality. I try my hardest to enjoy ranked. I think positively, I focus on my play, I don't flame. Recently I jumped back into ranked after a long break because of a friend asking me to duo with him. Being plat, we aimed for diamond. This is when I started noticing a problem I have with the mode. I heavily suffer from ranked anxiety. No matter how well we do, how high our winrate is, I'm always stupidly nervous when playing. Even if we were on a huge winning streak before, the moment I finally lose a game I get depressed and don't feel like playing more. These attitude problems really affect the quality of my play, and they are the main reason why I'm having a hard time achieving my goal, more than any feeders, trolls or afkers. So I ask, how can I get rid of ranked anxiety?