T.,
Have you registered with the local chapter of the NMSS? I also have MS, and our local chapter in Delaware has programs that offer emergency financial assistance, but you have to be a member of the chapter in order to apply. Once you register with them (can be done over the phone), they send you a whole lot of information and application forms. I'm not sure where you live, but the MS Society is also a wonderful resource for other support, information, etc.
Also, I'm not sure which meds you are taking, but sometimes you can apply for financial assistance with the manufacturer if you are not getting any insurance coverage to help offset the cost. I don't know too much about that end, but I'd try to call them, they certainly have enough customer service reps around with what they are charging for the drugs!
Good luck and keep a positive attitude! You should talk with your neurologist or primary care doc about possibly treating the depression as well - it's a pretty common ailment amongst MS sufferers and I think it might be worsened as a side effect of some of the drugs (Avonex, for example). Plus I don't think the depression drugs are too horribly expensive.
I hope you find the support you need.
Best regards, A.