Pete, most of us here know exactly how you feel because we've been there. This disease is very unpredictable and has many stages that you will go through. As you get older it usually becomes less painfull but your range of motion will be less and you may have fusion of the spine that leaves you in a stumped over posture. The more you do when you are younger the better you will be when you are older. Take your meds,get into a regular excercise routine including stretches and swimming (at least being in a pool) and eat properly along with keeping a positive outlook. I know how hard it gets at times and the flareups can be awful but like I said,it will get easier.
You're not alone my friend,
Steve.