Congratulations for discovering Buddhism and for being strong enough to stick with it in spite of your environment!
I grew up in the northeast and I can't even imagine what Christians must be like down south. However, lots of conservative Christians in America seem to like the Dalai Lama. Maybe you can use that fact to your advantage sometime, even though your preference is for Theravada.
You can feel compassion for these pushy Christians by thinking about how their minds are clouded by ignorance and attachment. In contrast, the Buddha saw things clearly. He clearly understood the true nature of the mind, the true nature of reality, and the way to end the suffering of all beings.
Putting a few Buddhist images up on the wall in my bedroom cheers me up and inspires me a lot. Perhaps putting up some Buddhist images might inspire you as well.
Best of luck with your Buddhist path,
Luke
