Have Multiple Sclerosis, Transitioning From RRMS To SPMS, Lost Weight, Dizziness. Finished IV Steroid, On Tysabri. Explain

I have had MS since 2000. I am now 42 and have just finished a week of iv steroid. My MS seems to be transitioning from RRMS to SPMS. Symptoms don't go away like they used to. Trying to recover seems harder every time. I started Tysabri in the fall of 2005 and was one of the ones pulled off it when PML was found. I don't think jumping ship to a new drug is a good idea because my disability has been relatively stable. I am rambling, I know, I just don't know what options are out there for SPMS. I really don't want to go on steroids again because this time around it was very hard coming off. I lost 6 pounds of fluid in one night and my dizzy head is now worse. Fatigue is worse also because of lack of good sleep. On a side note, in the last year I have had to have a partial thyroidectomy (found very small papillary cancer in a nodule) May 2012, and my gall bladder stopped working so it had to come out March 2013. Both of these surgeries required anesthesia and recovery from that was difficult due to short term memory loss. To get to my question, how realistic is it that my MS is responding to surgery and not progressing or transitioning?