What exactly are you self-hosting that’s gobbling up that much data? I’ve been self-hosting my website for decades and haven’t used that much over all that time let alone in one month.
Most of my bandwidth consumption is from torrents and downloading Steam games, but even that doesn’t get me to even 1tb/month.
This is pretty slick, but doesn’t this just mean the bots hammer your server looping forever? How much processing do you do of those forms for example?