Sleep! Please let me sleep!

[Joycey29]

Ok so we managed to get dd1 and ds1 sleeping through using a mix of reassurance and then with ds controlled crying.
Dd2 is another thing! I know she is only 21 months but I need some sleep. She can be up anything between 2-7 times and cries and cries. We even resorted to milk last night but she had a sip and handed it back.
I am back at work and need my sleep to be able to function properly!
Can anyone give me advice, tell me a book, or just let me know I m not the only Sleepless mother out there????