problems loging into back end

Hi to everyone.
I have been having problems with my new wordpress site, http://www.thegoodgift.co.uk, and it is driving me into total despair. The hosting account was hacked with malicious code being inserted and after deleting and cleaning implementing a new wordpress load I decided to putsome security in place and installed the “all-in-one-wp-security-and-firewall” which among other things changed to backend login from wp-login.php to a custom name. This worked fine for a day and a half and then my host account went incredibly slow and the ftp kept on timing out out as being unable to connect. This morning speed seems to be god but I cannot login to the backend. When I type in the website name plus the new redirect name it just shows the main page of the website. WP_login does what it now should and give a 404 page. So I am left with a website that shows but I cannot maintain it.
My question is where can I get into the back end code to either check the linking is correct or can I restore a file from a clean install or what can I do apart from deleting the whole thing and starting again.
I know the host account has been hacked because the log shows all types of users logging in from all over the world. It should only be me and hopefully this has now been fixed. My worry is the go slow was a ddos crack that broke the security again. HELP.
kind regards
Colin