Unfortunately, this instance and many others are being abused by bots and scrapers, and many have already had to shut down. The only current way of preventing this is to use Cloudflare services, and as decided from a community vote, this Cobalt instance will instead be taken down.
Thank you for using this server - over the past year, there have many people come specifically for Cobalt, and I'd like to personally thank you for supporting this host for so long. I recommend now directing that support to the developers of Cobalt and either use the official site or host it yourself.