Stop thinking about it. Make yourself ignore the 0/7 mid lane morgana (This is very hard), and just do customs until your cs is back up to par (aim for as close to perfect cs as you can get in a bot match without harassing the bot out of lane and use 0 runes / masteries and just a doran's blade).
This season's changes are attempting to force teamwork down the player's throats. I'd even wager that riot hasn't released solo queue solely because they want to force the player base into dynamic queuing.
Oh and pickup one of the strong but simple adcs. Like Kog'maw, Ashe, Miss Fortune, Ezreal, Corki, Graves where you can just focus on things like positioning / cs and ignore the mechanics and outplaying that is required for something like vayne. Abusing easy to play cheese picks is legitimately the best way to win in bronze / silver. They can't understand or figure out or implement the counter play and you can just pick it up in a few matches and run with it.
Try to never queue support in bronze / silver unless you play carry supports (Annie, Brand, Karma, Zyra, Morgana, Lux, Mal'zahar). Odds are your adc is going to be horribly bad with no wave control and without the slightest idea of positioning in team fights so you will have to carry them. Blitz is strong and does have decent kill potential but he just isn't as effective at straight up murdering everything rapidly like the actual mage supports are.
Tilting as a thing is literally getting nervous / angry and cutting off most of your brain's higher thought processes. Instead of a usual approach of looking at what is going on and deciding where you should be, you will just blindly rush into things like a crazed berserker. This happens because you are literally using the part of your brain that reacts in high stress fight or flight situations (Think of it as the same thought process you'd have if someone walks up to you and punches you on the street).
Literally the only way to avoid it is learning to just stay calm. Don't get negative over mistakes look at them neutrally and fix them. This is something very hard to implement and will take a lot of time. You'll know when your not doing it when you start having games where you feed or when your win rate suddenly plummets 20% or more (When I go 1.5 kda or less without at least 2 lanes being under 1.0 kda or having a afk for a portion of the match as a jungler I know that I failed at this. Another exception to this rule is when a lane feeds hard early game and then starts to make a comeback late. If the gold is split across multiple enemies and it's heavy feeding that is very hard to come back from. A good example of this is the 7/14/2 kog'maw I got in ranked 2 days ago. All of his deaths were early game to the point bot was like going into a 2 v 4. I died trying to force plays top / mid because they were the only hope of coming back into the game. The risk was accelerating the loss and the reward was a possible comeback ).
Either way the shifts towards being more of a team game are making things very hard. Getting uber fed just doesn't feel as effective as it did in previous seasons. All you can do is push your weight, ping objectives, and hope they do something smart with it. Actually this is probably why Udyr is perma bann now. He's one of the best champions for being a selfish solo carry. Tanky, good wave clear, and can escape or requires 5 man ganks (When fed) while keeping objectives pressured.
Making shot calls in chat even done politely will just start flame wars. People are ignorant and will rage thinking they're being told what to do or disagree and start a flame war. Something as simple as "I'll solo drag, you can take that bot tower" can turn chat into a middle school playground level of foul language and insults.
