For DD2 you could try a hammock or even one of those electric swings & slings can be very useful with Velcro babies, My DD2 was the same & the HAB worked so well for us.
As for DD1 we went through the same thing & she started sleeping through the night again once she got use to have a little sister, i'm sure your DD will do the same.

Your not failing those first few weeks are hard but things will get easier