I have never tandem nursed, but if you look at my siggy I do have a little experience with the two year age gap.
Give it about a year and a half to two years--you'll see why people plan it that way.

It's really hard in the beginning, especially when you don't have older ones around to help out, but you will get through this and watching the siblings' relationship blossom is going to be totally awesome, definitely worth the sacrifices you're making now.
DD1 is just going through a lot of adjustment right now herself, and she isn't benefitting a whole lot from this little needy baby, but when the baby can start playing with her and following her around, idolizing her big sister, it will improve.
