How do I explain to my Dr. that I want to stay on my medication?

I have been on an anti-anxiety medication that works for me. It is a medication that should not be used long-term but the only thing that works.....believe me, I tried other drugs over a 7 yr. period. I have another appt. soon and I'm afraid that my Dr. will suggest that I try to ween myself off this med. What is a good way to speak to a Dr. so that she will take me seriously and understand how important this is to me? THANKS for any help!!