Hello sir,
Firstly as u have AS then u have to do exercises regularly u should not leave the exercises
U should do basic streching exercises it will help u to maintain flexibility
U can do strengthning exercises but don't lift too weight. As your flexibility increses your muscles will work properly and this will also help to reduce some weight.
Next Steps
regularly check up should be done after some interval.
Health Tips
maintain the regularity of exercise and do the only exercise which u can do comfortably and increase repeatations and exercises slowly.