We used Ferber at 4 months, on the advice of our ped. I was spending literally 8 hours a day rocking DS to sleep for naps and bedtime and I literally thought I was going to lose my mind. I didn't stop night feedings, just put him down awake instead of rocking him and then soothed him in the suggested increments. It took two nights- 37 minutes total the first and 10 total the second. Yes, it broke my heart to hear him cry but I knew I couldn't handle the rocking anymore.
As far as night feedings, we eventually started to push them back in 15 minute increments and he finally started STTN at 8 months. Now, at 17 months, I still nurse before nap and night, but I put him down awake, kiss his eyes, nose, and cheeks, and he goes happily to sleep for 12 straight hours. So OP I highly suggest for both your sakes that you read and implement Ferber. Good luck!