I've been where you are! I posted last time under a different NN, with a lot of sympathy 
By 12 weeks I was nearly insane with lack of sleep. It is horrible. It DOES get better. (Slight disclaimer: I am assuming no long-term physical conditions preventing sleep here...)
I can't actually remember the point when it improved, but I do remember suddenly realising I was moaning about a single bad night that happened, rather than getting down on my knees and giving thanks for a single good night - so at some stage the balance just tipped, if you see what I mean. It's going to be different for everyone, but I think it was about 6-9 months in. It was definitely a LOT better by 12 months. Any upsets do set us back still in terms of sleep, but they tend to cause one or two nights' disruption, and then order is more or less restored.
Whatever you're doing, I would say just keep doing it consistently, because I think the only thing that really has an impact is repetition - the continuity of going whenever she calls, soothing, rocking, re-settling (and then doing it all over again half an hour later . White noise helped us a bit (a fan) as did an aromatherapy diffuser (in the living room for an hour before bedtime). The "usual" tips on improving children's sleep made absolutely sod all difference for us (getting them physically exhausted during the day, regular bath-time etc) because the sleep disturbance was emotional/psychological, not physical. In fact, getting LO physically shattered was actually worse, because they would conk out at bedtime, and then wake up in double the distress a few hours later as soon as their body had semi-recovered, when their brain seemed to go into over-drive. I just say this so you can feel free to ignore other people's advice if it doesn't feel right to you!
I grew to thinking of it as basically being on night shifts while LO was this disturbed at night. That helped me because it stopped me thinking I was going to be able to function very much during the day, and I dropped my expectations accordingly! Everyone was clean, fed, and safe. Not very much else happened TBH 