Definitely sounds like colic to me too I'm afraid. My dd, who is now 2 and a half had it very badly when she was a baby. It would start around the same time, approx 5pm and she'd scream for hours (until about 3am to start with and then it gradually got better in time, going to 2am, then 1am, then midnight, etc). I remember it only too well and can sympathise. Try and remember that it's not anything you're doing wrong and just comfort her as best as you can. And if it gets too much then just pop her down somewhere and walk out of the room for a few minutes to regain some sanity!
There are various things you can buy such as Infacol and Colief so do try them but also remember that it won't last forever and hopefully it should start to ease soon, I think they say that it usually goes at around 4 months when the digestive system matures which was true for us.
Good luck, hope it eases soon.