BF3 Sensitivity Help?!

Hi!
So. im having a bit of an issue regarding sensitivity in BF3. It feels like no matter what sensitivity i use, Real Slow, slow, half n half, fast, Real fast, my hand cant get comfortable.
Ive tried various things, to no avail. Any suggestions regarding what i should do?
I use a Logitech M570 thumb trackball, btw.
Thanks!
So. im having a bit of an issue regarding sensitivity in BF3. It feels like no matter what sensitivity i use, Real Slow, slow, half n half, fast, Real fast, my hand cant get comfortable.
Ive tried various things, to no avail. Any suggestions regarding what i should do?
I use a Logitech M570 thumb trackball, btw.
Thanks!