admin log in problem and redirect. theme lost

when I try to access https://www.yourdomain.com/wp-admin I am being redirected to

https://yourdomain.com/?page_id=50%2Fwp-login.php&redirect_to=http%3A%2F%2Fyourdomain.com%2Fwp-admin%2F&reauth=1

So, I’m not able to log in.
I am using Crazy Domains to host my site.

Also, when I go onto my website the content is all there but its just a white page with a few links.
The theme is not displaying at all.

This all happened at the same time while I was editing my site.

Can anyone help?

Thanks,
jess