You did not give a schedule of his day. What time does he wake up? Do you try to give him a morning nap? Does he have an afternoon nap? What times? What time do you all eat dinner and give him his bath to get ready for bed? What are your evenings like? Do you follow the schedule every day? How active is he?
Children need structure. A schedule is a great way to establish structure. As parents one of the hardest things is that we are not as able to be impromptu, because our children really need to know what is going to happen next. Also children's bodies need rest, but they also need some "very active time."
Try to establish a schedule so that each day you will get your work done, but he will also have time to be active. The more active he is, the more he will grow and the more tired he will be for his sleeping times.
If he wakes up at 7:00 am, make sure he eats a good breakfast. Give him some playtime with floor type toys. Then get him outside for a bit of active play. Running, climbing, throwing.. Let him be verbal, loud really active etc.
Then give him a small snack and maybe run an errand. Not longer than 1hr. 30 min. Then bring him home and give him his lunch and then a quiet time of a story and then a nap. Turn off all noise makers around the house. Your phones, tv etc.. Make sure his room is darkened, maybe play a quiet music CD or story CD. He can breast feed or give him a bottle while reading to him. Do not engage him in any conversation. Then Let him have his nap.
When he wakes up, more play with toys or helping you do "chores" , unload the dryer. Find all of the socks in the basket? Help me pick up leaves outside. Then another errand if needed or Very active play time. Hide and seek, races, pulling the wagon. Then time to get dinner ready. He can play on the floor next to you. Maybe stacking cans? Maybe a canvas bag filled with toys, putting things in the bag, taking things out of the bag. Show me the car, show me the ball. Playtime with dad and you but not too loud or active.
Have a nice dinner. Be careful not to be too loud. As long as your child gets really riled up it will take him to calm down. Sometimes twice as long. Turn off the TV.
Bath time should be quiet, and the house slightly darkened so that it does not look like there is anything interesting about to go on.
During the bath, have really warm water and use strong rubs like a massage. Then wrap him in his towel and carry him into a slightly darkened room. Dry him with strong strokes, use quiet voice tones. Breast feed him or give him his bottle while you read him a story.If he has a bottle, lay him in his crib while he drinks. When he is finished with his bottle, rub him slightly while you read. Read slower and slower while reading. Do not engage him with the book. Do not ask him questions. He should be pretty worn out.
If he wakes in the middle of the night, give him a few minutes, he may settle down. If he needs to have a diaper change, change him in total darkness, no conversations, then lay him down and he may go right to sleep. If he needs to breast feed do it in the dark, no conversation. Or make sure you have a bottle ready so you can give him a small bottle.
In the beginning getting him to sleep on his own may involve some crying. Just close the door and check on him in 5 min. only if he is crying. do not touch him, just peek and tell him "it is time for him to sleep". If he cries again, give him 10 minutes. then 15. etc.
Sometimes starting this new routine is best on the weekends cause there may not be much sleep for anyone in the house.
I am sending you strength.