No matter what anyone else says, ProduceDpt, I think the bottom line is just that this will get better in time so long as your are intending to improve, follow the steps the the best of your current ability, and PERSIST in your efforts! Maybe you'll find some really effective ways to break these habits along the way, but the odds are that if you persist in practicing the relaxation techniques of the PRWMS, you'll develop the ability to relax and move beyond incessant mental chatter!
For me, I used to get TONS of past memories -- totally random, usually, as I relaxed in any way, including for PHotoReading. My mind is much clearer now, however, as I've learned through practice and persistence to move my mind into that more peaceful state -- it's nothing that can exactly be taught to you, though.
-CameronJ