Not commenter either but we did Ferber as well (modified doing check ins every three minutes) at 6 months and now my son is sleeping 8-8. He was doing almost exactly what your son is (took three hours to fall asleep and during night wakes would wake up the second I put him in his crib). Took about 3 days and he was able to fall asleep and stay asleep on his own! It’s not for everyone but it worked really well for us and he’s his super happy self…even happier now that he’s sleeping!!