Antiobiotics and Temporary relief

I have a couple of questions about antibiotics alleviating MS symptoms.  I've been on 2 very strong antibiotics (which I know lower my WBC) for about 10 days now.  Saturday I started feeling like my old self again (with only a few symptoms still present); I had enough energy to take my children trick or treating around our neighborhood.  The next morning I was feeling it and my legs felt like lead; but I recovered after a couple of hours.

I've been on antibiotics before and they did the same thing; but the symptoms always come back.  My mind is clear for the first time in a long time; I can bring up words without thinking about them (however, if I try to think about it I still get hung up.)  But in my normal conversations throughout the day; I am flowing.

I can't stay on these antibiotics forever; they crash my immune system and then because of the MS; it kicks into overdrive to recover itself and then I get slammed with an attack.  Not to mention that it leaves me vulnerable to illness (The last time I developed viral pneumonia and spent 5 days in the hospital.)

Here are my questions  has anyone else experienced this and do they make a drug that will safely lower the immune system to a "normal" level?

Any information would be helpful!