And off-topic, Do counter picks matter at all in Bronze-Silver?
no, at below gold i would say you can 100% out play a losing match up if you understand both sides of it. In gold it starts getting fuzzy but it starts becoming a 50/50 thing. The higher you go up the more the counter pick can dominate a lane; assuming the counter picker knows the champ.
Though the higher you go up, you also find players that understand the match up and learn how to wait for their power spikes to turn the match around.
how to learn from my mistakes and start climbing quicker, and most of all not tilt.
get someone you trust to spectate a game and give honest criticism of what you are doing. It is always easier for someone to see your mistakes that for you to see your own. Just be willing to take the advice.
But what do i do when i find it alot harder to win games?
get better? I mean if you skill capping the answer is just to improve.
Here is a random tip. Most bronze games have the meta of chasing kills and go balls to the wall. Start asking your self do you really need to chase? Where is the rest of the enemy when chasing? Is there something else that could be done? IE dragon, tower, setting wave up to slow push?
Watch a bronze game and then compare it to a gold/plat/diamond game. Do not compare mechanics but instead what they are doing about positioning and objectives. See what you and others are not doing.