Hi and congrats on your baby girls! It is all a guessing game and I found the best way is to gradually work through any possible causes rather than try them all at once.

In the meantime to help you cope.
let her sleep on your chest if you can get some peace - I spent a good couple of months with DS sleeping on me and it helps - you get rest, they get rest and it helps everyone cope with the other problems
have you got a sling that you can use, preferably an upright one like the huga bub to help when bub is awake?
Have you tried brauers colic relief or stomac calm from the chemist - natural homeopathic solution

next are you BF or formula feeding?
How is the wet and dirty nappy situation
is she gaining weight?
Does she cry at particular times more so than others
when is she not crying?

Something I found really interesting with DD was to actually write down how much time she did cry it can either make you feel better as you see she isn't crying as much as you thought she was, or if she is crying a lot might help the proessionals find an answer if it gets to that point.

All the best, hope it gets better