My warts WON'T go away!! Help?

I'm now fourteen and I've had warts since I was 7. There is a large one on my knee, multiple on my right thumb (6 in a clot, one in the middle, and one on the other side.), one on my right middle finger, one on my right pointer finger, and one on my left middle finger. I've tried everything - duct tape, medicated wart pads, liquid nitrogen, etc. They come off and the skin is normal, but they reappear in the same spot again. Is there some type of antiviral medication I could take to reduce the warts and keep them supressed? The ones on my right thumb are slowly wrapping around my thumb and they have completely taken over my cuticle. Thanks in advance for any and all suggestions xx