Most definately AMartin.
Move gradually and progress at your body's own pace and ability. Sitting is quite fine. You may even just sit ( or lie) and visualize the movements, when your body is too tried to do the exercises standing or sitting. WITH TIME YOU'LL GET THERE!
Don't rush it. Relax, smile, breathe, and enjoy the practice.
We're all honored to have you with us, and thanks for your sharing.
Thank you,
Mike