The problem is you are playing against people like us that have been playing since release date.
We'v got hundreds of hours of experience and know all the hiding spots, the way the map flows, and crucially how to use the spotting mechanic to our advantage. All of the times you've been turned around and shot upon is because you've been spotted.
If you're finding it frustrating you can either keep trying until you learn, or just give up and maybe pick up BF4 and then start on a level playing field.
Yeah you're probably right, its just that I am used to the spotting mechanic, as Ive played BC2 for years with the same spotting mechanics. Perhaps BF3 players spot more than BC2 players though. I expect I'll wait for BF4 and be on a level playing field, though I will quickly fall behind as I cant put in the hours that some will, thats not anyones fault nor the games fault of course though.