I just got to Hardmode, and after a bit of exploring, I noticed that there is a huge Hallowed biome to my east right next to my jungle. The hallow has already eaten up a desert of mine, and it's slowly spreading more and more. I live on a snowy mountain and to the west is the corruption. Sunflowers no longer protect me, so I put down some Hallowed seeds to stop the Corruption, but now i'm afraid everything is going to be engulfed in the Hallow. I feel like the mountain is slowly being pushed by the Hallow on both sides. What do I do?