You can do something simple like allowing only your IP address access to your WordPress Login page in the link below permanently or temporarily IF you are the only person that logs into your site. ie you do not allow anyone else to register, login and post comments on your site.
https://forum.ait-pro.com/forums/topic/protect-login-page-from-brute-force-login-attacks/
We have several sites where we need for people to be able to register, login and post comments. So during larger scale brute force login attacks we have seen 1,000 login attempts per second for up to 3 days. During the attack the forum site loaded .1 seconds slower than normal. That was the only negative impact and everything else worked as usual – new user’s were successfully able to register, login and post comments. Basically we were aware that the attack was going on, but no one else was – business as usual. ??