I Need Help with Sleep Training!

My 8 month old son (first child) is terrible about sleeping. Every nap he fights and cries. At night he prefers to fall asleep on the boob and wakes up sometimes four times a night still. We tried sleep training a month ago and it was a massive fail. Since then we decided to just tackle one problem at a time - taking away his night feedings and promoting solid sleep from midnight to 4am. No go. He doesn’t self soothe and works himself inside out if we don’t feed him. We’re all dying here and need help.

Do any of you other moms have a suggestion for a method/book that worked when you started later or already had sleep problems? Although I’m wildly jealous of you moms whose children just sleep well on their own, that situation doesn’t apply to us.