HI Nicola
If you go back to the main page and then to the AS Patient Guidebook, I have a series of exercises posted there that many people has said that help. My hips were so bad 4 years ago that I couldn't walk down stairs (and I was a marathoner). I am running most days now. So I tell you this to inspire you to have hope. Hopefully once the fusing and inflammation goes down, you will have more freedom. Keep swimming and let me know if these exercises help, or if you need more help.
Best Regards!
Ellyn