I know, so many people shout, "I'm stock!" at the beginning of a match. It's not clan wars, no one gives a shit! It shouldn't make or break a pub battle, and by Tier 7 you should know how to use a stock tank just as well FFS. That's not to say you're not going to be better with all the upgrades, but for shit's sake, you're not a useless hunk of metal totally stock in any tank whatsoever.
I just wish I could learn how to play this game and not suck. I gave up on playing again because I'm just horrible at tanks in general. I'm impressed with my win rate on my IS, and only my IS. Everything else sucks ass, or worse, and my win rate with mediums is beyond shameful.
I'm embarrassed to even put it in here, but here it is:
I don't know how to get better from here.
Here is my advice. Take a step back to a tier 1 or 2 tank. They are all basically the same: No armor to speak of, guns that can pen eachother decently (except the ultra armored H35 variants), about equally fast, etc. You see less maps, you can figure out ways to exploit certain things on maps (I am looking at you himmelsdorf). You learn the importance of flanking, staying the hell out of the firing lines of TD's (which will stay with you for life), understand when a push can help win a flank and when it is suicidal (something I have yet to learn with my 17k battles).
Give this a go, take a tier 1 tank (highly recommend MS1 (use the 45mm gun)), buy your crew to 75% (or retrain a crew from another tank back down to this one for 80/90%). You play a grand total of 4? maps in tier 1: Province, Mines, Himmelsdorf, Campinova.
On mines, regardless of what tank you picked, try to go to the top hill, or at least get your gun to cover the top hill. Learn how to be hull down by using the terrain. Do NOT suicide to make it to the hill, denying the enemy the hill is good enough.
On Province, head south/north along the ridge and learn your spotting limitations, sight limitations, and cover along with the proper way to snipe and/or being a passive scout.
On himmelsdorf, never go hill in a tier 1, takes too long. Instead pick the 3 line each and every time, learn where the rubble is, how to best angle your tank to get bounces, and know that you may have to back up and save base. Also you learn not to overextend.
On campinova, if you start in the north side, try to make it quickly to the range of bushes infront of the wall at spawn and passively scout. Only shoot when you are spotted (you will know based on when the enemies guns suddenly look RIGHT at you). On the south, go along the hill by the water to the grove of bushes. Passively scout. You will spot any enemies going through the marsh as well as anyone going through town. Depending on your crew skills, you might even spot stuff on the top hill.
I know you have 2k games under your belt, and this is pretty basic stuff. But once you master these 4 maps and know how to exploit the situation, I would then advise taking this knowledge to the mid/higher tiers. Mid tier is all kinds of screwed up with the 105 HEAT spam, unless you are joining in with it, avoid tier 5 like the plague. If you already understand and do these things, then you can ignore this message.