I would recommend the following book:
Overcoming Anxiety: From Short-Time Fixes to Long-Term Recovery by Reneau Z. Peuifoy. Amazon carries this book.
I have been through these kinds of feelings when switching medications. One med had me walking into walls and it felt like I was on the outside watching myself with comprehending why I was behaving this way. At the time I was also under severe stress.
Breathing exercise:
There are different types of deep breathing strategies, but the simplest involves sitting in a chair with your back straight and your arms on the armrests. You take a deep, slow breath in through your nose lasting close to 5 or 6 seconds. You then hold for a few seconds, and breathe out slowly through your mouth, taking close to 7 seconds (breathe out like you're whistling). Repeat 10 times.