Every time I am in this website, after a while, the website resets for me and then I try to put my username and password in, but it doesn’t even register that I made an account earlier.

Hello! I'm sorry to hear about the issues you're facing.

Are you using any extensions on the browser you're using for D&D Beyond? 

Did you use Twitch or Google to create your D&D Beyond account?

Yes, I tried to do twitch and google but they didn’t work, so I think the problem was resetting my history, and it’s working fine for now.