Can't login to my wordpress Dashboard, Why?

I really don’t understand why suddenly I cannot access my dashboard on wordpress.

When i click this https://myfunfoodiary.com/wp-admin/
It states like this “safari cannot open the file….. because the server dropped the connection. This sometimes occurs when the server is busy. Wait for a few minutes and then try again”

Tried many times but still nothing happened.
But nothing wrong with the web page : https://www.myfunfoodiary.com

Can someone help me to solve this?

Thanks so much in advance.