I need help! my son used to sleep all through the night since he was about 2 months old. he is 6…

I need help! my son used to sleep all through the night since he was about 2 months old. he is 6 months now and he wakes up about 3 times at night and will not go back to sleep unless I soothe him as in rock him or put him in bed with me. that is the only way that I myself can get sleep. he is teething and he has been eating food. I think it is because he isn't getting enough to eat.. I am huge on a bedtime schedule but it seems that I follow it and it doesn't do a thing cuz he still wakes up. I'm exhausted