How can i get my 8 month old to sleep through the night please help?

my little boy has never slept through and he is now 8 months he is on a good routine and a rigid bedtime routine and always self settles and goes off to sleep on his own with no help from me but he is till waking every 3-4 hrs at night for a feed he is bottle fed and takes 4-7oz every time he wakes he is on solids now and has breakfast lunch and dinner and approx 10oz of milk in the day time and only has three 30-45 mins naps a day but he still is not sleeping through at night he goes down at 7.30 and has a bottle then and then he wakes at 10pm 1am 4am 6am and then get up at 8am iv tried everything and nothing is working my health visitor has advised controlled crying but im very hesitant any advice would be fab as im slowly going insane with sleep deprivation