Hey, this is part of the game and it should be hard. These events last for 2 minutes, the more you kill the more will spawn. Low health? Just run in circles, build fire or torch (they hate it). Use your bow more often. Build a fence or a wall around your base. Don't stay in your base, they will attack your house, just go outside, they will follow you.
And watch some videos on youtube, maybe this will help. Spoiler, Trolls will be a bigger threat. :D