Hi, dreamn! I have a Pilates video titled, Beginning Mat with Ana Caban, that's produced by Gaia. On the video, one of the instructors demonstrates how to modify each exercise to make it easier. There's also a 20 minute introduction that explains the best form for each exercise.

When I started, I couldn't keep up with the tape either. Take it very slowly, and maybe learn one (modified) exercise at a time. It takes a few weeks, but you can learn them all over time, and you don't have to do all of the exercises in order to benefit from them. The other thing I could recommend is to buy a book so you can practice at your own pace without the time pressure of the tape--I have one called, Pilates Body in Motion that has diagrams for each exercise, and I know there are many others around and/or on Amazon.

Or, if you live near a Pilates studio, maybe invest in one private session where the instructor can show you how to modify the workout for your own needs. The certified trainers are fantastic at working with people's limitations--the studio I go to has people with leg, back, and neck problems, and some are significantly overweight or, in my case, rather elderly.

Please don't give up on Pilates--it's wonderful, and it really does work! Good luck to you. Hope this helps.