Admin login fails

I logged into my account several weeks ago. Today, I can’t. I seem to be having trouble in two areas:

1. When my password is rejected at my website’s wp-login.php, I click the Lost Password button and an email with a link to reset the password shows up in my mailbox. However, clicking the link results in an error (something like “This key is invalid.”). This occurs when trying to access from wifi.

2. I can’t access my website in a browser on any computer in my home. Both the www or the wordpress login php result in a “can’t connect to server” message. However, I can access the website and FTP to it from my cell phone using cell connection.

If I try logging in using a cellular connection, then my username is accepted but my password is rejected. I’ve reset my password using my host’s MySQL interface. (I also changed my email, too, to make sure changes at the host’s MySQL were actualized–WordPress does use the new email to send me the reset password link.)

Any suggestions?