Did you have a sex drive before you went on contraception ?
iI so your doctor might be trying to find one that doesn't interfere with your sex drive. From what my girlfriend says they definitely affect her sex drive.
It would be nice though if your doctor was a a lot more supportive and telling you what she is trying to do.
If you aren't happy with your doctor, it might be worthwhile getting a second opinion from another doctor. I changed my doctor a couple of times until I found one who was thorough and didn't treat me like an idiot when I asked them something. He always tells me what he is doing and why.
They can maybe run some tests to see what your hormone levels are like. (Eg testosterone).