Afraid it may be permanent

I have pretty much clear skin in fact I'm about 99% acne free but a few months ago I got this huge pimple on my nose Its the only pimple I have and its been here since about February. Its in the center of my face on my nose and it seems to go down and then flare back up again. I popped it once and it did the normal pimple thing...(gross details left out). Then It just comes back I went to the dermatologist and she just prescribed me doxycycline and I've been using that for about 2 weeks and it doesn't seem to be doing anything

I've been using benza-clin very heavily on this one spot, cleaning it, using hot rags, and alcohol twice daily ever since I got the thing but it just seems to keep going down and coming back help!!!

PS. It's not really hard doesn't hurt but it is a bump, theres a small (very small, smaller than a pin head) white head on it but I really don't want to touch it. So I think Its probably bad stuff still in there...