Quite frankly you just have to get better at the game. Climbing through Plat is pretty similar to climbing through any other League. You can try and figure out something strong in the current meta you can exploit or just focus on your fundamentals until you get more consistent wins.
If you're bothered by anyone in chat, remember the mute button is your friend!
As you can see. It is quite hard to climb in these situations (Too much toxicity). But For me, I guess just stay cool, chill. It'll help a lot in games.
As what Mayuran95 was saying. Go for the champs you feel that it's easy for you to use (Much better if you're playing support, just my opinion)
I'm not sure what role you main, but i can give you some general tips.
1. Stick to 2-3 champs(MAX) for each role you are playing.
2. Know and play around your powerspikes! Every champion has a point in the game where they become significantly more powerful. For example: Corki gets a massive powerspike when finishing trinity force and Sorcerer's Shoes. Yasuo gets a powerspike when finishing Phantom Dancer + Infinity Edge. Ekko gets powerspike when finishing Protobelt + Lich bane and so on. It's a window of opportunity where you MUST make stuff happen, and you should abuse this every game to get a lead!
3. Mindset is key - People tend to give up fast when they/teammates get smashed in lane. Just don't FF and keep trying your best... Why? Teams usually make more mistakes when they are ahead because they don't know how to close out games fast. When they keep making mistakes, they will eventually get tilted, and that's your chance of making a comeback.
4. Focus on OBJECTIVES not kills. That's how you end a game fast.
5. As PsiGuard said, mute negative people. I don't use chat for anything else than timing summoners and abilities. If your team starts talking/flaming too much, just mute them and focus on your gameplay only.
If you're bothered by anyone in chat, remember the mute button is your friend!
As what Mayuran95 was saying. Go for the champs you feel that it's easy for you to use (Much better if you're playing support, just my opinion)
1. Stick to 2-3 champs(MAX) for each role you are playing.
2. Know and play around your powerspikes! Every champion has a point in the game where they become significantly more powerful. For example: Corki gets a massive powerspike when finishing trinity force and Sorcerer's Shoes. Yasuo gets a powerspike when finishing Phantom Dancer + Infinity Edge. Ekko gets powerspike when finishing Protobelt + Lich bane and so on. It's a window of opportunity where you MUST make stuff happen, and you should abuse this every game to get a lead!
3. Mindset is key - People tend to give up fast when they/teammates get smashed in lane. Just don't FF and keep trying your best... Why? Teams usually make more mistakes when they are ahead because they don't know how to close out games fast. When they keep making mistakes, they will eventually get tilted, and that's your chance of making a comeback.
4. Focus on OBJECTIVES not kills. That's how you end a game fast.
5. As PsiGuard said, mute negative people. I don't use chat for anything else than timing summoners and abilities. If your team starts talking/flaming too much, just mute them and focus on your gameplay only.