Depending on how your AS progresses and what part of the world you live in, you should have a normal life expectancy. That can be shortened by lack of adequate treatments or AS affecting the internal organs, such as the heart or lungs.
Life will be more challenging, but with adequate care and support, you can still live a good life. You have to find your new normal.
AS is chronic and progressive but with an adequate care plan you can stall the progression or put it into remission for a period of time.