How To Relieve Pain In Knee Joint And Hip?

hi there
i have been diagnosed with ankylosing spondilitis a couple of years ago and for the last few years it's been managable regarding my back stiffness - i struggle to sleep at night and wake up very uncomfortable in the morning especially if i have tried to have a lie in. I have now started to get aching in my knee joints when i'm lying down which means i cannot get comfortable at night for this reason too - is this probably linked to the condition and is there anything i can do to make this more comfortable in the evening? I have also hip pain in one of my hips which has come on over the last few weeks and didn't know if this was linked to me and my husband going for longer walks of up to 10 miles of a weekend or was possibly linked with the condition too. The hip pain has meant that currently I am not able to sit cross legged on the floor to play with my son when in the past that has been my seating position of choice. I have a few months till my next check up at the hospital so just was after an opinion.
Many thanks
Nicki (36)