Keeping a log? Interesting idea. I should start to keep one myself. I mostly keep a "mental log".
Anyway, I thought I'd also lend you a piece of advice or more. As someone who started in Bronze 2, dropped to Bronze 5 out of rage (yeah, I was a bit less smart in S2) and then climbed to Silver 3 in S3, Silver 1 in S4 and Gold 3 this season (Go me! I'm Gold 5 now, though; I swear one of these days I'll get to playing ranked again).
So, here's my first and (I think) most important piece of advice: Play the game. A LOT! Don't expect to climb the ladder in the minimum number of games possible. Don't make calculations like "oh, I'll just need 2 more wins to get to promos and then another 2 to promote", it will not happen. The best you can hope for is to make it in 10 games (maybe, maybe more). The idea is to play a lot and you'll eventually get better and hence higher on the ladder. I think I played some 150-200 games from Bronze 5 to Silver 5.
My second piece of advice: Listen to what Koalifier said. There's no reason to keep track of afks/trolls when losing. You will however benefit from looking a bit more in-depth at what you can improve and what you did good that you should keep doing.
My final piece of advice: Play anything. Be versatile. Don't just fulfill one role. Sure, it's good to have a position in which you know what you're doing. But you know what's even better than that? Knowing all roles/positions. Now, of course, I'm not ridiculous. You don't have to be an expert at everything, but at least be good enough that you won't lose one aspect of a lane, say CS, or K/D ratio, or maybe even vision control on your side of the map. I played more than half of my games in Bronze as a support. It's amazing what you can do with a role when you know it well. Especially when nobody wants to play that role, because that means that you know it better than your opponent who only took support because he was last pick.
I hope that this helps. Just a bit of advice from someone who has been where you are. It's not impossible to get out of "elo hell" (even if you play mainly support). Anyway, I wish you good luck in the games to come. ^_^