We have just been through this very same horrible phase. Google four month sleep regression for some refreshing news, it's totally normal and a phase and I have lived through it to tell you she has passed it and now sleeps 2-3hourly( 2x a day and a 40 min cat nap at the end of the day... bed at 6pm feed at 10pm, wake between 6/7am!!!) sometimes waking at 40minutes with a tiny grizzle and back to sleep. There was a thread on here about it too I think???