Teach me to be a coward

Understand the game is won by resource control. Laning is about taking over the minion line, not killing the enemy. Midgame is about taking over the jungles with wards, taking out towers and dragons, and maintaining minion line control. By playing around these things you can supress your enemy unless they come to you. If they won't, you get the gold advantage.

play Soraka, Janna and Bard. You will learn really quick how to not always being going ham. AP supports in general are a good pick as you become acutely aware of how fragile you are with AP support items.

play a farm champion like nasus and just farm THEN Go fuck e eryone up

I have a similar background and had similar problems when I first started playing. If you're anything like I was your real issue is tunnel visioning so you get ganked and your aggression is off timed and perhaps sloppy. Learning support will help to round you out a bit, but I otherwise wouldn't worry. I'm still an absurdly aggressive player and I'm about to enter Gold V.

I think you're confusing cowardice with patience and opportunism. Like don't engage someone until a specific ability of theirs is on CD. Wait until they use it and fail at it. Like a Blitz grab or Ezreal's blink or Vladimir's pool. That's when you go ham. Or a more frequent timing on know how to trade comes from simply watching the hp of your own minions. When one gets low the enemy will try to last hit it. While they are taking the moment to attack a minion you should attack them. They won't be able to retaliate right away. Otherwise you can try to last hit their minions and place yourself a safe distance away so that they cannot hit you while you try and last hit.

And the person above me listed support champions, namely the passive ones. Soraka and Janna are extremely passive being a sustain/poke style champion. They have very low kill potential so they just try to win trades and back off ASAP. I guess you can also throw Nami in with Janna and Soraka even though Nami is more of a poke/sustain champion. Braum is in a whole nother style of supports. Braum fits into the sustain/kill catergory along with Alistar and Taric. They're opportunistic killers because they excel at counter engagements. Braum can soak up the damage from poke style laners, Alistar can thwart any gap closers or instant engagers who try and jump his carries and Taric has a never-fail point and click stun and an ultimate that gives a HUGE boost to his stats making him a highly immobile castle. Playing any of these champions means you do a lot of sitting back and waiting on the other guy to make a mistake (Braum, Taric and Alistar) or covering up the mistakes of your own teammates (Janna, Soraka and Nami). But patience plays a key role in playing these champions well.

I'll also give you a lesson on the 3 styles of laning: Kill, Poke and Sustain. Every champion has 1 style they excel at, 1 style they are mediocre at and one style they are inefficient or incapable of using. And the laning styles function a lot like a game of rock, paper scissors. Sustain beats poke, poke beats kill and kill beats sustain.

The kill style champions are straight forward. They win by killing the other guy. They are flashiest of the three styles and they typically have abilities or passives that incentivize killing the other guy. High damage, sustained damage output and ability resets are clear indicators of a kill laner. Champions like Draven, Darius, Katarina and Kha'zix are prime examples of this play style.

Poke style champions COULD kill you. But that's not their objective. They do deal damage but they often do it from a safe distance where they can burst someone down and quickly get out before the other guy retaliates. They win by making the other guy back before they do, getting kills is just a bonus. These champions are identified by having a long range, burst style damage output and a mobility or crowd control ability. Champions such as Xerath, Caitlyn, Gnar and Nidalee are best used this way.

Sustain style champions are the stalwart immovable champions who just take a beating and carry on about their business. Their objective is to focus on CSing and heal back or mitigate any poke the enemy laner(s) deal. They also have some crowd control or mobility that usually helps them escape trouble should they ever find themselves in it. They win by outlasting the other guy. The other guy will run out of mana or patience before they kill a sustain laner. They are detected by having heals, peels, shields and occasionally mobility. The champions who epitomize the sustain lane play style are Soraka, Warwick, Irelia and Vladimir.

Pretend there is always a rengar sitting in that bush you are cloesest two unless its warder. Not just any rengar but a fed af rengar who has max build. That will teach you to facecheck, and overextend while you try to 1v1 mid.