you're original question was "how do you know when you are winning your lane?"
Winning your lane means that you gain more gold than your lane opponent during lane phase. If you buy bad items it doesn't matter if you win your lane.

It's kind of a mixed bag of questions and situations that make me wonder if i'm actually winning my lane.

Usually if you have more farm plus a kill above your oponent, you could consider yourself winning your lane right?

Well the reason why i asked is because despite having more farm and a kill, graves would come back to lane and still deal more dmg and push me back to my turret.

as a side note, its true that obama was only elected cuz hes black

If you are building Black Cleaver EVER you're doing it wrong. And he will continue to 1v1 you.

I play Graves often and I also find myself going up against Ezreal a lot. The lane is not as heavily favored towards Graves as you feel it is, and really supports play a big role in the matchup.

There are 2 pieces of advice already stated in the replies that you seriously need to take.

First off you can blink dodge Buckshot using your E to get out of the way. Since Buckshot comes out in a cone/triangle shape, that means the most effective way to blink to maximize your chances of not getting hit is TO THE SIDE AND TOWARDS HIM. Keep practicing this and don't hesitate, reaction speed is very important in dodging skillshots.

Second thing you need to do is stop building Black Cleaver on Ezreal. If you build Bloodthirster you will leech life back and you will last longer in fights, therefore increasing your chances of winning the fights. There are a few different builds that work effectively on Ez, but none of them really involve Black Cleaver. I'm not necessarily saying BT rush is the best (lots of people prefer Triforce), I am just suggesting you to upgrade the BF Sword you get into a Bloodthirster, which is a much better choice than a Cleaver.

This is the way I estimate it.

15 CS = 1 Kill. (Although kills can lend themselves to earning more or less CS)
Blowing up the enemy turret can be counted as a kill for this purpose.

If your CS + Kills * 15 > Enemy AD CS + Kills * 15, you have a gold advantage.

If your gold advantage is larger than 30 CS or 2 kills, you won your lane.

When you blow up the enemy turret or they blow up yours that's when "who won the lane" is set in stone.