Hi,
Just wish to offer my support and my experience. My DS was sleeping 13 hours then stopped. For 3 months we struggled on with betting up 4-5 times a night. End result was that he was hungry, I'm still b'feeding but for a while there gave him up to 100mls of cows milk from 10 - 11 months of age to settle him at night, worked a treat for us. I also used to add a bit of oatbran to his dinner to add a bit of bulk in his tummy. After these 2 things he was straight back to his earlier sleeping habits.
Anyway that's our experience. hope it helps
Turned out I was starting to cycle again and then got pregnant possibly leading to him not liking my milk for a while.
hope you find some answers and a solution soon.