How to show My own ASPX page (As Login page) when i do custom authentication in sharepoint

Question

I have a requirement that i need to implement custom authentication in sharepoint and the login credentials should be EmailAddress & Password. once i given this it should check the details in my own sql server database instead of SharePoint database. And based on that it should allow the user to see authenticated page. Its a public site so the login page should not be SharePoint default page. It should be my own page say "ABC.aspx".

I didn't get any clues from my google search.

If any body have any idea pls share with me.

Thanks B.N.Prabhu.