Sleeplessness during night. Depressed.

My son is finding difficult to settle to bed, he wakes up hourly and cry.. Difficult to console. Reluctance to food..eats some specific foods that he likes. Started walking 1 month back. Didnt start speech yet. I am 8 months pregnant. He needs my presence during night and i am getting weak day by day..he is not having continues sleep. He had gas problems and difficulty in drinking breast milk until he was 6 months old..but he never slept peacefully at night..he used to sleep during day time and wide awake at night..now he sleeps less than 1 hour day time.but still he is not sleeping continuously at night .consulted a pediatrician and according to blood test vitamin d3 is given for 10 weeks. Even if he is sleeping i couldnt lie him to bed as he wakesup and cry.he is lying on my leg on pillows. He is normal during day time without even a single cry..but gets irritated when he feels sleepy but shows reluctance to sleep..i am helpless.consulted Many but in vain. I am getting depressed.