If you're having trouble starting Apache because something is already bound to port 80 (and it's a hanging instance of Apache), it's possible that you simply need to kill the process the hard way and manually start it so you can enter your SSL Certificate passphrase.
Error: "Address already in use: make_sock: could not bind to address 0.0.0.0:80
$ sudo netstat -ltnp | grep ':80'
$ sudo kill -9 #### (the process ID of apache2 from above)
$ sudo service apache2 start