As another low talent player who probably learned the wrong way at the start as well: it sucks man, I know.
Here's some unasked for advice:
Try playing a bit on both relax and auto pilot. It can become more obvious if your problem is within aim or accuracy.
If accuracy:
Check whether you have an offset problem. Turn on the bar thingy that shows in game and hover over the graph after you finish a map to check how you're doing. If your offset is constantly in one direction, change your universal offset or practice technique.
If your offset is bad (200+ unstable rate), but not necessarily in one direction, even on easy maps, then that's probably your issue. If you're unstable, higher OD maps will kill you no matter how hard you try. You can only hope to be as accurate on fast maps as your top accuracy on slow maps. So practice your unstable rate on slow maps.
Take an easy/normal where the notes have very obvious counterparts in the music and with a high note count, mod it to OD10 and AR8/9 and practice and practice and practice that unstable rate. Make sure that you have the highest frame rate limiter set if you're doing most of your timing with your eyes and also try playing it on HD to force yourself to use the music/internal timing more.
Really focus on following the accuracy on higher speed maps. Don't bother with aim for a while (play on auto pilot if you want), just try to get a balance of 300/100s that is shifted as far towards 300s as possible.
If aim:
Try to really focus on small parts of aim. Like making straight lines. Play a bunch of maps while thinking about nothing else than making straight lines between the notes. Don't even look at your accuracy afterwards, it doesn't matter, you just want to make straight lines right now. Make it part of your system.
Do the same again, but focus on hitting notes exactly in the middle, rather than somewhere on the edge.
Do the same again, but focus on finishing sliders completely.
Do the same on any area you feel you might be weak in, then practice all of these things again.
If you're having trouble following your cursor, try out some different skins.
. When i'm depressed I PFC easy and normal diff. (once nomod and again DT (+HR) if I feel I can. 
