my heart goes out for you- you are doing an amazing job just surviving with so little sleep- be proud of yourself!
You've recognised its time to make a change and there is so much help out there, in no time I'm sure you'll be able to put things in place to improve the situation!

I have just finished reading Elizabeth Pantley's No cry sleep solution- and I tell you it was written exactly for your situation!!! If you can get it I would definitely recommend it!
I would also recommend sleep school, they dont make you do proper controlled crying but possibly a little more crying than you'd be happy with? but for so many people it is the turnaround point!