I've noticed that when I'm not playing well, I will continue to do so for that gaming session. My advice to you would be to decide what kind of player you want to be. Do you want to run and gun or be more cautious and camp more. Both have their pros and cons so maybe a little of both. I think a good K/D is more important than how many kills you get so I always wish mine was higher (last time I checked it was around 1.25) but I am more obsessed with my accuracy (it fluctuates between 23%-25%). I think that a slower more cautious pace is better for a decent K/D. Learn the maps and learn what areas on the maps players gravitate towards and try to be there as much as possible. I don't camp a whole lot myself but when I do it's in areas more as opposed to just one specific spot.
As far as starting a new account, I'd wait a while if I were you because you will most likely get better than you are now and you can use your current account as practice.
I LOVE paying for Xbox Live! I also love that my love for it pisses off so many people.
