Hi Bunnyhoppin: The reason that they use this music is that research has shown that people actually spend more when they are energized. Companies hire psychologists to analyze their marketing to increase sales.
In any case, it sounds like it is more likely that your anxiety rather than ADD that is interfering with your concentration. You might want to read my recent sharepost at Anxiety Connection about PTSD. While my article may not address your specific cause of PTSD, we know from years of experience that hypervigilance, inattentiveness, jumpiness and super sensitivity to sounds, light, smells or sudden movements can have a negative impact on your day to day living.
I assume you have a therapist, and perhaps he/she can help you desensitize to these stimuli. If you don't have one, find one who specializes in PTSD. You can locate a therapist in your area through Psychology Today.
I hope this helps,
Dr. Diana Walcutt
The Stress Masters