Tips and tricks for fussiness!?

My daughter is now 8 weeks old and the doctor "says" she's got colic and reflux so I've switched her formula to Enfamil nutramigin for colic and she's also on Zantac and Levison drops...but about 4pm-1am She's screaming on and off every 5 or less minutes for hour periods then finally relaxes to sleep for about four hours. I'm at my end with this crying and trying to comfort when I've literally dome everything....I'm just so tired of seeing her hurt and cry and I can't help her at all it seems. I need advice I'm very stressed tired and frustrated?!