Anxiety is a completely normal emotion to feel when one learns anything new for the first time.
I remember in the beginning questioning myself as to 'Will I ever master this?' 'This seems like so much to know and remember' ... take is SLOW. Practice often and remember, Time is your ally!
Revisit the tape's again ... you'll be amazed at how much more you pickup the second time round. This is a great confidence booster as it helps to allievate the every questioning mind. Since you're on tape two ... keep forging ahead.
Here's something you can try. If you find yourself unable to relax ... try exercising (running, jogging or anything aerobic 10-20 minutes) if your health permits, shower, drink PLENTY of water and try your PR session.
Your should also know that when you tilt your head down, the body has a tendancy to automatically want to relax.
Relaxation caused by anxiety will subside in time once you learn to use and trust the system.